Device and method for transporting substrates in a printing machine

ABSTRACT

The object of the present invention is to provide a novel device and method for accurately transporting printable substrates suitable for substrates of various types, sizes and thicknesses. In addition, the invention is suitable for printing machines without contact with the substrate, such as inkjet printing machines.

The present invention relates to the field of printing, in particularthe field of digital printing without contact with the substrates, andmore particularly a device and a method tier transporting printable andprinted substrates on all of the treatment stations in a printingmachine, the transport of the substrates being performed in a way thatallows them to be printed under optimal conditions.

INTRODUCTION

The transport of substrates using automated treatment or industrialmanufacturing is a particular technical challenge. Part of thedifficulty lies in the movement of a substrate along a chain comprisingseveral treatments of the said substrate, in particular its movementfrom one treatment station to the next, during themanufacturing/finishing process of the final substrate. Any device fortreating a substrate, and more particularly any device for digitallytreating a substrate, may advantageously benefit from the advantages ofthe present invention. By way of a purely illustrative and non-limitingexample, the substrate-treatment device is selected from devices forlaser cutting, finishing, drying, punching, cutting, folding and/or inparticular printing, particularly digital inkjet printing.

This technical challenge of transporting a substrate is furthercomplicated when combining different types of printing and/or dryingwithin the same machine. Conventional (mono- or polychromatic) and/or ofvarnish printing inks, and/or printed electronics, and/or drying,comprising, e.g., an infrared (IR) and/or near-infrared (NIR) and/orheated airflow drying oven, and/or ultraviolet (UV) and/orlight-emitting diode (LED) UV drying, and/or a photonic process may bementioned as purely illustrative and non-limiting examples. In fact, thecombination of several printing modes and various treatments within thesame machine requires a transport mode of high precision (e.g., in orderto meet the requirements of printed electronics), as sell as a transportmode, in which the components do not affect the efficiency requirementsof each of the printing and treatment stations separately and/or incombination; the negative impact that a treatment station may have on apreceding treatment station and/or on a following treatment stationalong the transport path (e.g., in order to prevent a drying stationfrom affecting the performance of a printing station) may be mentionedas an example. Moreover, implementation must be such that optimalconveying of the variously sized substrates between all the treatmentstations is made possible, while the requirements related to thedifferent speeds of each of the treatment stations, as well assufficient manufacturing rates in order to allow for efficient andcost-effective industrial application are also met.

PRIOR ART

Transports of printable substrates performed with suction belts intendedto hold a substrate against said moving belts are known from prior art.Nevertheless, this type el solution, which is well known to thoseskilled in the art, has some disadvantages. In particular, this type ofdevice, giving rise to air movements and pressure gradients, may causedeformation of the substrates, if these substrates are large. Printingaccuracy will thus be compromised. On the other hand, the use of thesesuction belts with some widely used printing technologies, especiallyinkjet printing, can cause accidental suction of the ink present in theprintheads and thus dry out the printheads. This type of incidentrequires, in the best case scenario, reprinting of the printheads, andin the worst case scenario, replacement of the dried-out printheadshaving become, in fact, unusable.

To mitigate these problems, in particular in order to allow precisemovement of substrates, prior art teaches techniques using cylindershaving a plurality of clamps gripping the substrates by their leadingedge relative to the direction of substrate movement, Although this typeof solution is suitable for inkjet-type printing machines, it still hasseveral disadvantages. In fact, this system requires that all inkjetheads be arranged in an orbital fashion around a large cylinder.Furthermore, the difficulty of adjusting the position of the printheadsfor this type of system poses a problem. In fact, for quality printing,the ink ejected from the printheads must form a jet, whose direction isperpendicular to the surface of the substrate. It is obvious that, inthis case, the use of a cylinder for transporting and tightening thesubstrate, whose surface is by definition not flat, involves cumbersomeadjustment of the printheads positions. This is also what makes the useof substrates of variable thickness difficult, as changing the substraterequires adjustment of all the printheads. On the other hand, theprinting pitch, i.e., the position of the cylinder clamps is fixed,which means that the printing rate remains the same, regardless of thesubstrate size.

Prior art also teaches substrate transport systems using chains orconveyors, upon which are arranged clamps for gripping the substratesand transporting them on a transport path, a portion of which is flat,which solves the problem of the arrangement of the printheads. However,this type of solution still present the problem of a fixed printingpitch, which imposes a fixed rate and thus creates the additionalproblem of not being able to use differently sized substrates withoutstopping the printing and proceeding to make a cumbersome adjustment ofthe clamp positions.

More recently, the Applicant, in their WO2013156540 patent application,proposed a device and as method for transporting printable substrates ina precise fashion, suitable for substrates of various types, sizes andthicknesses, and for making possible variable-pitch printing. Itdiscloses a substrate transport system in a printing machine along atransport path oriented along a longitudinal axis from at least oneentry magazine providing the printable substrates, to at least onemagazine exit receiving the substrates, characterized in that itcomprises movable gripping means, each comprising an opening/closingsystem ensuring the release or gripping of a substrate, said grippingmeans comprising front and rear gripping means, gripping a front andrear portion, respectively, of the substrate along the transport path,guiding means for guiding the gripping means along the transport path,at least one drive means ensuring movement of the gripping means alongthe guiding means, preferably with an independent movement between atleast the front gripping means and the rear gripping means, thesubstrate transport system being thus suitable for gripping eachsubstrate so as to tighten and move the substrates, even if of variablelengths, along the transport path, the guiding means, the gripping meansand their associated opening/closing system being controlled by computermeans.

Although the device and the method of WO2013156540 already verysufficiently meet the needs of those skilled in the art, the Applicanthas now developed a device and, a method for improving the transport ofprintable and/or printed substrates on all the treatment stationsincluded in a printing machine, in particular, a printing machinewithout contact with the substrate, such as inkjet printing machines.

EP1977893 (A2) claims a conveyor comprising an elongated guide defininga closed transport path extending through a plurality of treatmentstations, a plurality of supports movable on the guide along the course,and each capable of holding a workpiece to be machined, at least onemagnet on each support, a row of electromagnets that may be poweredindividually and extending along the path and capable of exerting aforce on the magnets of the supports in order to move the respectivesupports along the course.

US2013293652 claims a device handling a substrate sheet in a labelingassembly, the device comprising a support track (path) forming a closedpath, a labeling area for labeling a substrate sheet, and acarriage/tray movable along the support track, the carriage/traycirculating around the closed path, the said carriage conveying thesubstrate sheet in one process direction on at least one portion of theclosed path through the labeling area. As shown in FIG. 4 , the carriageis provided with front and rear roller wheels, which support thecarriage 80 along the bearing surfaces of the track, said trackincluding side walls, which appropriately hold the carriage between themon account of the side wheels (provided with springs 86), which help toposition the carriage sideways along the track 40. US2013293652 does notexplain the mode of movement of the carriages and merely mentions theoption of having a built-in motor, a propulsion via a mechanism includedin the track 40, or a direct drive system, using pulleys, cables, chainsor other similar systems.

US2015137446 claims a card-treatment system comprising a card treatmentsystem, comprising a treatment device configured to sequentially processindividual cards, a carriage configured to hold an individual card andmove the card toward the treatment 2D device and a transport loopassembly configured to support the carriage, the carriage comprising adriven roller configured to engage the loop and move the carriage alongthe loop, the driven roller being operatively connected to a drive forcreating rotation of the driven roller.

INVENTION—INTRODUCTION

The present invention thus provides a novel device and method forprecisely transporting printable and printed substrates suitable forsubstrates of various types, sizes and thicknesses. In particular, theinvention makes it possible to produce variable-pitch prints. Inaddition, the present invention is suitable for printing machineswithout contact with the substrate, such as inkjet printing machinesand, more particularly, printing machines making a possible to combine,within a single machine, different types of printing and/or dryingand/or pretreatments and/or post-treatments (or finishes), such as,purely for illustrative and non-limiting purposes, conventionalcontactless-printing inks (black, white, mono- or polychromatic), and/orvarnish, and/or inks suitable for electronic printing, and/or inkssuitable for three-dimensional printing, and/or various and sundry inks,such as functional inks and/or insulating inks (e.g., insulating inksused downstream of an ink print for electronic printing); and/or dryingcomprising, e.g., an infra-red (IR) and/or near-infrared (NIR) and/orheated-air drying oven, and/or ultraviolet (UV)-lamp and/or UVlight-emitting diode (LED) drying, and/or a photonic process; and/orpretreatment, such as a corona-treatment station, and/or aplasma-treatment station, and/or a tape-cleaning system (cleaningroller, brush, etc.), and/or a coating station (flexography, etc.),and/or a sheet-turning system; and/or post-treatment (or finishing) ofthe substrate in a coating station (e.g., by applying an additionalcoating, e.g., gilding or other material), e.g., by means of a “gilding”application device, e.g., by applying/pressing a sheet (carrying thesaid coating or gilding) onto selected areas of the substrate (e.g.,comprising an adhesive deposit in a predetermined pattern) in order forthe desired portion of the gilding-type sheet to adhere to the selectedareas; moreover, this combination of several printing modes and/orvarious treatments within the same machine is made possible by thehigh-precision transport mode (e.g., for meeting the printingrequirements of electronic printing) according to the present invention,while preventing the transport components from altering the efficiencyrequirements of each of the printing stations and/or the individualand/or combined treatments (e.g., to prevent a drying station fromcompromising the performance of a printing station). The presentinvention also makes it possible to convey the variously sizedsubstrates between all the treatment stations, while meeting therequirements related to the different speeds of each of the treatmentstations, as well as sufficient production rates to enable efficient andprofitable industrial application.

INVENTION—GENERIC DEVICE CLAIM

Thus, the invention relates to a device for transporting substrates in aprinting machine, comprising one or more treatment stations, includingat least one printing station, along a transport path from at least oneinput area (e.g., a magazine) providing the printable and/or printedsubstrates, to at least one output area (e.g., a magazine) receiving theprocessed substrates, comprising:

-   -   1. a substrate conveyor (preferably of the carousel type) for        guiding and moving the substrates through the treatment        stations, said conveyor comprising:        -   a. A fixed rail, which forms a transport loop; and        -   b. Carriages, which hold the substrates in a stationary            position (e.g., immobile and flat), and which move on the            said rail, while carrying the substrates and;    -   2. An input area for the substrates (e.g., a substrate storage        input magazine);    -   3. An optional substrate transport system from the input area to        the carriage;    -   4. An optional transport system for the treated substrates from        the carriage to the substrate output area (e.g., the output        magazine);    -   5. an output area for the treated substrates (e.g., an output        magazine for storing treated substrates);    -   6. an optional siding for the carriages, said siding being        removably connected to the conveyor rail and thus allowing for        the addition and/or removal of one or more carriages;        the substrate-transport device thus adapted for moving each        carriage/substrate assembly, i.e., moving it by moans of the        carriage on the rail along the transport loop, and characterized        in that    -   1. The substrate-transport device comprises a base on which at        least a part of the rail is fastened and whose surface is        preferably plane;    -   2. The substrate-transport device comprises a drive system,        which allows the carriage to move fin the fixed rail;    -   3. The carriage comprises a table (preferably a suction table)        for holding the substrate in a stationary position relative to        the table (e.g., immobile and flat), along the transport loop,        during the treatment(s) of the substrate        characterized in that the drive system is a linear drive system        based on the principle of electromagnetic interaction between a        coil assembly (primary assembly) and a path of permanent magnets        (secondary assembly), and the primary motor assembly of the        linear drive is part of the mobile carriage, and the secondary        assembly consists of a path of magnets (magnetic path), said        path being fastened on the fixed rail and/or being an integral        part thereof, and/or being fastened on the base and/or forming        an integral part of the base, and/or fastened on a rigid        structure for holding the rail and/or forming an integral part        of this rigid structure.

Other features and advantages of the substrate-transport device aredescribed in more detail in the present application. A further object ofthe invention is to propose a method of transporting printablesubstrates.

INVENTION—GENERIC CLAIM PROCESS

Thus, the invention also relates to a method for transporting substratesalong a transport path, implemented by the substrate-transport deviceaccording to the invention. In particular, the invention furthermorerelates to a method of transporting substrates in a printing machine,comprising one or more treatment stations, including, at least oneprinting station along a transport path from at least one input area(e.g., a magazine) providing the printable substrates to at least oneoutput area (for example a magazine; receiving the treated substrates,characterized in that the method comprises the following steps:

-   -   1. Optional positioning of a printable substrate in the input        area (e.g., storage of a printable substrate in an input        magazine);    -   2. An optional substrate transport system from the input area to        the carriage;    -   3. Guiding and moving the substrate through the treatment        stations by a substrate conveyor (preferably of the carousel        type), said conveyor comprising:        -   a. A fixed rail forming a transport loop; and        -   b. Carriages, which hold the substrates in a stationary            position (e.g., immobile and flat), and which move on the            said rail carrying the substrates; and    -   4. Optional transport of the treated substrate from the carriage        up to the output area the output and storage magazine for the        treated substrates);    -   5. Optional displacement of carriages to a siding, said siding        being releasably connected to the conveyor rail making it        possible to park and/or add and/or remove one or more carriages        from the conveyor;        the substrate-transport method being thus adapted for moving        each carriage/substrate assembly, i.e., displacing it by means        of the carriage on the rail along the transport loop; and        characterized in that    -   1. The substrate-transport device comprises a base, upon which        at least a portion of the rail is fastened, and whose surface is        preferably plane;    -   2. The substrate-transport device comprises a drive system that        allows the carriage to move on the fixed rail;    -   3. The carriage comprises a table, upon which the substrate is        held in a stationary position relative to the table (e.g.,        immobile and flat) along the transport loop during the substrate        treatment(s)

characterized in that the drive system is a linear drive system based onthe principle of electromagnetic interaction between a coil assembly(primary assembly) and a permanent magnetic path (secondary assembly),and that the primary drive assembly of the linear drive is a part of themobile carriage and the secondary assembly consists of a path of magnets(magnetic path), said path being fastened on the fixed rail and/or beingan integral part thereof, and/or fastened on the base and/or forming anintegral part thereof, and/or being fastened on a rigid structure forholding the rail and/or forming an integral part of this rigidstructure.

In a preferred embodiment of the present invention, the substrate isheld flat in a stationary position relative to the table; however, asthe present invention can be applied to sheet-like substrates, andequally to any other type of a three-dimensional object (e.g.,cylinders, pens, telephone casings, etc.) it will be appreciated bythose skilled in the art that the invention may also advantageously besuitable for these other types of objects, whose immobile positioningmay not be qualified as “flat” on the table; according to an alternativeembodiment of the present invention, the upper part of the table willcomprise a matrix comprising shapes and/or receptacles, in which theseother types of three-dimensional objects may advantageously be depositedand/or fastened.

The present invention also relates to the use of the claimed deviceand/or of the claimed method for transporting the substrates in aprinting machine, comprising at least one contactless printing station,in particular for digital inkjet printing. More specifically, thisutilization is obtained in a printing machine that comprises at leasttwo different serial, contactless, printing stations, the said printingsbeing selected from the following list:

conventional printing inks (black, white, mono- and/or polychromatic),and/or varnish, and/or inks for printed electronics, and/or inks forthree-dimensional printing, or varied and sundry inks, such as, e.g.,functional inks and/or insulating inks (e.g., insulating inks useddownstream of an ink printing for printed electronics); the combinationin series on the transport loop of conventional ink printing, an inkprinting for printed electronics (such as conductive inks, whether ornot based on nanoparticles) and priming of varnish and/or functionalinks and or in ink, all carried out preferably on a single substrate,represents a preferred utilization of the present invention.

Furthermore, according to a particular embodiment of the presentinvention and, as described in detail in the following specification,the claimed device and method differ from the prior art due to theirflexibility of use and the reduction of manufacturing time, as well ofas related costs, which makes them especially attractive, particularlyfor printed electronics, e.g., the manufacture of printed circuits.

Other features and advantages of the substrate-transport process aredescribed in detail in the present application.

INVENTION—FIGURES

The invention, with its features and advantages, will become clearer,when reading the specification in reference to the accompanyingdrawings, wherein:

FIGS. 1-13 schematically illustrate several aspects and embodiments ofthe invention.

The present invention has many advantages over the prior-art techniques.These advantages offered by the present invention will be furtherillustrated in the detailed description of the figures.

Generic Software

In a preferred embodiment of the present invention, the transport device(and thus the printing machine, comprising one or several treatmentstations) is controlled by computer means, which, in particular, controlthe various workstations, and, moreover, gather information from thevarious sensors installed in the device. These computer means need notbe described in detail in the present application and they may beintegrated, e.g., in the machine or externally in a separate device. Thesensors provide, e.g., substrate positional information, substrateconfiguration information and/or validation information, following acorrectly or incorrectly performed operation. Some information necessaryfor the implementation of the invention may also be pre-entered into thecomputer means (e.g., by an operator via a data-capture interface). Suchinformation may, e.g., relate to the shape and/or dimensions of thesubstrates (e.g., their thickness), the drying power, the thickness ofthe layer of ink and/or varnish, etc., but it is generally preferredthat sensors measure or verify such information. The substrates awaitingprinting are generally placed in a per-se known manner in at least oneinput area, e.g., an input magazine with a storage capacity definedaccording to the nature of the substrate and the printing requirements.In an exemplary embodiment, an input magazine is provided in order toreceive several tens, hundreds, or even thousands of substrates ofvariable types, thicknesses and dimensions (for example, and withoutlimitations, of a format, whose sides are on the order of onecentimeter, e.g., a type A10 format, a more specific example being acredit-card-type format, up to a format, whose sides are on the order ofseveral meters, e.g., a type A0 format or a 2×2 meter format). Uponcompletion of the printing process, the substrates are guided toward anoutput area, e.g., stored in at least one output magazine havinggenerally the same storage capacity as the input magazine.

Generic Displacement

A feature of the present invention is therefore the use of a substrateconveyor (preferably of the carousel type) for guiding and moving thesubstrates through the treatment stations, the said conveyor comprisingcarriages, which hold the substrates in a stationary position (e.g.,immobile and flat) and which move on a fixed rail, allowing each socarriage/substrate assembly to move on the rail, and characterized inthat the displacement of the carriages on the fixed rail is controlledby means of a drive system, preferably a linear drive system. Thislinear drive is based on the principle of electromagnetic interactionbetween a coil assembly (primary assembly) and a path of permanentmagnets (secondary assembly), an interaction that converts theelectrical energy into linear mechanical energy. In a preferredembodiment of the present invention, the primary motor assembly of thelinear motor is part of the (mobile) carriage, and the secondaryassembly consists of a path of magnets (also referred to as a magneticpath), the said track being fastened on the fixed rail (or forming anintegral part of the fixed rail), and/or fastened on the base (orforming an integral part of the base), and/or fastened on a rigidstructure for holding the rail (or forming an integral part of thisrigid structure); in this configuration, the primary carriage assemblythus moves at the same speed as the substrate transported by the saidcarriage. The carriage can thus be described as an intelligent and/orautonomous carriage, as is done below in the specification.

The length of the path of magnets is preferably similar to the length ofthe fixed rail or the transport loop. Configurations, in which themagnetic path is located on either or both sides (in a multi-pathconfiguration) of the fixed rail may be considered. Thus, the totallength of a path of magnets may have a length that is identical,slightly greater or slightly less than that of the fixed rail; forpurely illustrative and non-limiting purposes, the magnetic path willhave a length between 0.8 times and 1.2 times the length of the fixedrail, preferably between 0.9 times and 1.1 times the length of the fixedrail.

The advantages of this drive technology are numerous. For illustrativeand non-limiting purposes, we mention:

-   -   The direct coupling of the mobile carriage to the moving part of        the motor, which eliminates the need for transmission elements,        such as drive belts, rack gears or worm gears, ball screws, etc.    -   There is little or no mechanical wear, as there is no contact        with the moving parts, resulting in excellent reliability and a        long service life;    -   The possibility of individually controlling the speed and/or        acceleration and/or deceleration of each carriage; it is also        important to note that this individual control can be done at        any time and/or at any point of the transport loop, unlike the        device claimed in EP1977893 (A2), whose supports are controlled        by a section predefined by the electromagnets arranged along the        transport path; it is also important to note that this        individual control may be different for each carriage for any        given location,    -   Reducing the number of mechanical components in order to        minimize maintenance and thus reducing the cost of using this        technology.

FIG. 1 provides a schematic overview of the substrate-transport deviceaccording to the present invention. It shows the carousel-type substrateconveyor for guiding and moving the substrates, said conveyor comprisinga fixed rail, which forms a closed transport loop (in the figure, arectangle with rounded corners); carriages (three carriages in thefigure), which hold the substrates (three rectangular substrates percarriage) in a stationary position (flat, in the figure), and which moveon said rail carrying the substrates, the center fixed rail, as well asthe magnetic path positioned at its center; the fixed base (whose lengthis slightly less than one length of the side of the rectangle formingthe transport loop, in this illustration); as well as a simplified viewof the electrically conductive rails, which, in this configuration, forma closed loop (with the same shape as the transport loop) of a greaterlength than the fixed rail, as it is located outside the loop formed bythe rail. To make it easier to understand this figure, the treatmentstations were not shown; for purely illustrative purposes, thepositioning of the printing stations along this transport loop coincidewith the position of the base so as to fully benefit from the advantagesof the present invention.

FIG. 2 provides a schematic view of the secondary assembly, whichconsists of aa path of magnets (also called a magnetic path), said pathbeing fastened on the fixed rail, in this illustration. It is alsopossible to identify in FIG. 2 , the base, the electromagnets, the dualV-guide at the ends of the fixed rail, as well as the two slidessituated on either side of the fixed rail, the said slides beingexplained in detail in the specification below.

Device—Overview

FIG. 3 provides a schematic overview of the substrate-transport devicein a printing machine comprising a plurality of treatment stationsaccording to the present invention. It shows the carousel-type substrateconveyor for guiding and moving the substrates through the treatmentstations, the said conveyor comprising a fixed rail, which forms aclosed transport loop, and carriages (not shown), which hold thesubstrates in a stationary (e.g., flat) position and which move on saidrail carrying the substrates, a substrate storage input magazine to theleft on the figure, a substrate-transport system for the input magazineup to the carriage, a system for transporting treated substrates fromthe carriage up to the output magazine, and a storage output magazinefor the treated substrates to the right on the figure. The “Alphajet”block located at the top left on the figure and in this configurationpositioned inside the loop reflects the printing and drying stations;particularly in this configuration, a combination in series ofconventional ink printing, the printing of inks its suitable for printedelectronics (such as conductive inks, whether or not based onnanoparticles) and varnish printing and/or functional inks and/orinsulating inks.

Transport Loop

A feature of the present invention is thus the use of a substrateconveyor (preferably of the carousel type) for guiding and moving thesubstrates through the treatment stations, the said conveyor comprisingcarriages, which hold the substrates in a stationary (e.g., flat)position, and which move on a fixed rail, which forms a transport loop,e.g., a closed transport loop. The shape of the transport loop may be ofany suitable type. Its length will itself be determined according to thenumber of treatment stations included within the printing machine. Inparticular, the printing machine according to the present inventioncomprises at least one printing station not in contact with thesubstrate (e.g., two, three, four or more printing stations) and atleast one drying station two, three, four or more drying stations); theprinting station may advantageously be selected from a conventionalinkjet printing station (black, white, mono- and/or polychromatic) anfor a varnish jet printing station, and/or an inkjet printing stationadapted to printed electronics (e.g., conductive ink, whether or notbased on nanoparticles), and/or an inkjet printing station adapted forthree-dimensional printing, and/or a printing station with various andsundry ink jets, such as functional inks and/or insulating inks (e.g.,insulating inks used downstream of an ink print for printedelectronics); the drying station may advantageously be selected from aninfrared drying station (IR) and/or a near-infrared drying station (NIR)and/or a heated air drying station, and/or an ultraviolet (UV) lampdrying station and/or a UV light-emitting diode. (LED) drying stationand/or a drying station by phototonic process. For illustrative andnon-limiting purposes, we mention the optional use of one or morepre-treatment stations, e.g., a corona-treatment station, and/or aplasma-treatment station, and/or a strip-cleaning system (cleaningroller, brush, etc.), and/or a coating station (flexography, etc.),and/or a sheet-turning system; and/or the optional use of one or morepost-treatment (or finishing) stations, such as, e.g., a sheet-turningsystem and a coating station (e.g., by applying an additional coating,e.g., gilding or other material) on the substrate, e.g., by means of a“gilding”—application device, e.g., by applying/pressing a sheet(carrying said coating or gilding) unto selected areas of the substrate(e.g., comprising an adhesive deposit in a predetermined pattern) so asto make the desired portion of the gilding-type sheet adhere to theselected areas. This combination of several printing modes and/orvarious treatments within the same machine is made possible due to thehigh-precision-transport mode according to the present invention, whilepreventing the transport components from impacting the efficiencyrequirements for each of the printing stations and/or treatmentsseparately and/or in combination. The present invention thus makes itpossible to convey the substrates of various dimensions/sizes betweenall the treatment stations, while meeting the speed requirements(whether they be different or identical) of the substrates, passingthrough each of the treatment stations, as well as providing sufficientmanufacturing rates to allow for efficient and profitable industrialapplication. The drive technology, in particular the linear-drivetechnology, used for transporting the substrates makes it possible tocontrol the speed of each carriage separately; this then makes itpossible to accelerate or decelerate the speed of a carriage uponrequest, or change the speed of one carriage relative to another. Hence,in a particular embodiment of the present invention, at time “t”, thespeed of at least one carriage (transporting substrates) moving alongthe transport loop varies from the speed of a another carriage(transporting substrates) moving along the transport loop; for example,the speed of at least one transport carriage moving substrates through atreatment station varies from the speed of a carriage transportingsubstrates moving either through another treatment station or othersections of the transport loop. This ability to individually control thespeed and/or acceleration and/or deceleration of each carriage, as itmoves along the transport path, represents an exceptional advantageaccording to the present invention. This affords the possibility offully benefitting from the performance of each of the treatment stationsby adjusting the speed of the carriage according to the type oftreatment desired. Thus, in a particular embodiment, the presentinvention also allows for printing and/or drying, and/or variousvariable-pitch treatments.

In a particular embodiment of the present invention, the transport loopdoes not comprise a right angle; on the contrary, its shape willpreferably be selected such that it comprises only linear straight partsjoined by means of free-form curves (“arcs”).

Naturally, other alternative embodiments are conceivable for thetransport loop. For illustrative purposes, we mention the variant inFIG. 4 , in which the carriages do not follow curves (turns), whenmoving along the carousel; shown are the carousel-type loop, sixcarriages, each supporting a substrate “A,” each substrate beingstationary on its designated carriage, as is the direction of movement,represented by arrows, of each of the carriages.

For illustrative purposes, we also mention the variant in FIG. 5 , inwhich the carriages do not follow curves (turns) during, their motion,and the loop comprises at least one rail (e.g., two parallel rails)situated at a certain height, and at least one rail (e.g., two parallelrails) perpendicular to the first rail and situated at another height,which involves the use of a system for raising and/or lowering thecarriage (like an elevator) in order to pass from one rail to another.

Even if these variants are not preferred in the context of the presentinvention, they could nevertheless be useful, e.g., in the case there isa limited amount of available space for installing the transport device,whereby this inconvenience would call for more compact transportsolutions.

In a particular embodiment of the present invention, the transport loopis square or rectangular and with rounded corners.

In a particular embodiment of the present invention, the treatmentstations, e.g., the printing and/or drying stations are situated in astraight linear portion of the transport loop.

The usual rotational direction of the carriages along the transport loopis generally defined according to the arrangement of the printing and/ordrying stations and/or alternative substrate treatment stations(s).Thus, it may be clockwise or counterclockwise. Another advantage of thelinear drive technology according to the present invention is theability to reverse the rotational direction, if required. Hence, in aparticular embodiment of the present invention, the carriage and thesubstrate(s) held in a stationary (e.g., flat) position on the carriagemay move in either rotational direction on the transport loop. Thisfeature makes it possible to obtain, e.g., more than one passage in aprinting and/or drying station and/or another station for treating thesubstrates, and/or in a combination of two or more, or all of theseaforementioned positions. This flexibility can be particularlyadvantageous, e.g., in the case of temporarily reduced performance oraccording to the relevant type of treatment station; by way ofnon-limiting illustration, a treatment station may require repeatedpassage[s] of the substrate in order to attain the desired printingresolution (for a printing station) and/or the desired drying quality(e.g., for a drying station, whose drying power, one would not want toincrease) and/or one may have to perform multi-passes, when not neededfor other treatment stations. Controlling the movements of the carriagesin an autonomous fashion thus constitutes a considerable advantage ofthe present invention. Thus, the carriage can be described as anintelligent and/or autonomous carriage, as done below in the presentspecification.

In principle, the substrates only pass the loop on their selectedcarriage after being held in a stationary (e.g., flat) position on thecarriage near the input and substrate-storage magazine up to their pointof their removal from the said carriage, near the output and treatedsubstrate-storage magazine.

However, and this represents an additional advantage of the presentinvention, two or even several transport-loop passes are conceivable forthe substrate. Thus, in a particular embodiment of the presentinvention, the substrate may perform more than one pass in a printingand/or a drying and/or alternative-substrate treatment station, and/orin a combination of two or more or all of the above, without leaving itscarriage. This feature may be particularly useful, when a printing,and/or a drying and/or alternative-substrate treatment station does notattain the required performance, e.g., as regards printed-imageresolution for a printing station; i.e., a second pass under the stationwith reduced performance will solve this problem without having tochange the defective station in a rush.

Base—Rail—Wheels

A feature of the present invention is therefore the use of a substrateconveyor (preferably of the carousel type) for guiding and moving thesubstrates through the treatment stations, the said conveyor comprisingone or more carriages that hold the substrates in a stationary (e.g.,flat) position, and which move on a fixed rail along the transport loopduring the substrate treatments, and characterized in that at least aportion of the rail is fastened on a base, whose surface is preferablyflat; the length of the fixed rail being preferably identical to that ofthe transport loop.

FIG. 6 schematically illustrates this base-rail assembly. It shows, forillustrative purposes, a granite base, which forms the dark gray base,upon which a fixed rail with a double V-guide is fastened; there is anoptional holding, part, which is fastened on the fixed rail, and uponwhich is fastened, on its left, a ruler, which will be described in thespecification below, and on its top, the path of magnets alreadydescribed above. FIG. 6 also illustrates, in a very schematic way,elements, which will be described in more detail in the specificationbelow, i.e., slides, on either side of the fixed rail, fastened on thebase, and at the left edge of the figure, a set of electricallyconductive rails with a radiating cable transferring (information) dataon top.

The dimensions of the base will be selected according to therequirements and applications. By way of non-limiting illustration, andfor industrial applications particularly covered by the type of deviceclaimed, the upper flat surface of the base will be arranged at a heightoff the ground of between 50 and 80 cm, with a transverse width between40 and 120 cm, e.g., between 60 and 100 cm, and a length of between 200and 1,200 cm, e.g., 500 and 800 cm.

In a particular embodiment of the present invention, the total length ofthe base(s) of the transport device is selected such as to cover theentire space below the printing stations of the transport loop. Moreparticularly, if the total length of the printing stations is the valueX, the total length of the base(s) of the transport device will be atleast X, so as to guarantee the desired flatness under the printingstations; however, as one or more of these base(s) represent(s) a loadand a significant financial investment, it is preferable to limit theirtotal length to values less than 3 times X, preferably less than 2 timesX, e.g., less than 1.5 times X, i.e., less than 1.2 times X.

In a particular embodiment of the present invention, the total length ofthe base(s) of the transport device is likewise selected, such as tocover the entire space below the drying stations of the transport loop.More particularly, if the total length of the drying stations is thevalue Y, and the total length of the printing stations is X, the totallength of the base(s) of the transport device will be at least (X+Y), soas to guarantee the desired flatness under the drying and printingstations; however, as one or more of these base(s) represent(s) a loadand a significant financial investment, it is preferable to limit theirtotal length to values less than 3 times (X+Y), preferably less than 2times (X+Y), e.g., less than 1.5 times (X+Y), i.e., less than 1.2 times(X+Y).

In a particular embodiment of the present invention, the total length ofthe base(s) of the transport device is likewise selected, so as to coverthe entire space below the other treatment stations (which are neitherprinting, nor drying stations) of the transport loop as pre- and/orpost-treatment stations, by way of illustration. More particularly, ifthe total length of the other treatment stations is the value Z, thevalue of the total length of the drying stations is Y, and the totallength of the printing stations is the value X, the total length thebase(s) of the transport device will be at least (X+Y+Z), so as toensure the desired flatness under all drying, printing and othertreatments stations however, as one or more of these bases represent aload and a significant financial investment, it is preferable to limittheir total length to values less than 3 times (X+Y+Z), preferably lessthan 2 times (X+Y+Z), for example less than 1.5 times (X+Y+Z) i.e., lessthan 1.2 times (X+Y+Z).

In an alternative embodiment of the present invention, the total lengthof the bases) of the transport device is less than half the length ofthe transport loop, less than 0.4 times the length of the transportloop, e.g., less than one third of the length of the transport loop.

In a particular embodiment of the present invention and, moreparticularly, depending on the length of the transport loop and/or thelayout of the printing and/or drying and/or another treatment stations,one, two or several bases will be provided in the transport device.

The base, its flatness and dimensions therefore represent importantfeatures according to certain variants of the present invention. Thus,the base forms the stable foundation/solid seat of the transport-looprail at the most critical locations, e.g., below the printing stations.More particularly, the Applicant has found that the base makes itpossible to effectively solve the vibration problems encountered withthe prior-art transport devices, thus making it possible to improve thetransport of printable and/or printed substrates for the whole of thetreatment stations, including in a printing machine, in particular aprinting machine without contact with the substrate, such as inkjetprinting machines. This explains the choice of a polishable firm rock,generically referred to as marble, such as, e.g., granite, and/orbasalt, and/or porphyry, and/or serpentinite, . . . and/or gneiss,and/or sandstones, and/or gaps, and/or limestones and/or otherconglomerates, as component(s) of a base used in a preferred embodimentof the present invention. It is obvious that those skilled in the artwill know how to select other materials, whether or not similar tomarble, which similarly al meet the requirements of the absence ofvibrations in order to ensure the quality of prints; by way ofillustration, we mention, e.g., granite (a generic term used inconstruction and designating any natural material having the appearanceof a rock, which is generally very solid and wear-resistant), and/orcomposite stones, and/or ceramics, and/or technical ceramics, and/orcast iron. Moreover, the Applicant has found that the weight ratiosbetween the base, the carriage and the substrate(s) were importantfeatures for combatting the vibrations of the transport device; thus, inan alternative embodiment of the present invention, the ratio betweenthe weight of a carriage of a length L and the weight of a length L ofthe base will be less than 0.3, e.g., less than 0.2; in an alternativeembodiment of the present invention, the ratio between the weight [of acarriage of a length L and substrates arranged on said carriage] and theweight of a length L of the base will be less than 0.3, e.g., less than0.2.

Any carriage guide system on the rail may advantageously be used in thecontext of the present invention. In a particular embodiment of thepresent invention, the carriage guide system on the rail is selectedamong the V-guide systems; preferably with a double V-guide, as shown inFIG. 6 (a rail with V-shaped “male” ends) and FIG. 7 (V-shaped “female”wheels fastened on the carriage). In a particular embodiment of thepresent invention, the carriage comprises at least one V-shaped wheel,preferably two V-shaped wheels, more particularly at least four V-shapedwheels.

According to a preferred embodiment of the present invention, the guidesystem for the carriage on the rail comprises at least one pair of guideelements arranged on either side of the rail (e.g., wheels), each pairof guide elements (e.g., a pair of wheels) having a mechanism forguiding the carriage in straight sections, as well as in turns. By wayof non-limiting illustration, each pair of guide elements will comprisea support bar connecting the two guide elements (e.g., the two wheels)with one another, the said support bar comprising a pivoting axisconnected to the carriage to ensure optimal guidance of the carriagealong the rail and, in particular along the turns formed by thetransport loop.

In a particular embodiment of the invention, the guide system for thecarriage on the rail comprises three guide elements (e.g., threewheels), two on one side and one on the other side of the rail, so as toallow the carriage to make the turns created by the transport loop andalso follow the linear directions.

FIG. 7 thus illustrates a carriage variant according to the presentinvention, said carriage comprising a structural base shown in lightgray in the figure with a table dark gray) on top for supporting thesubstrates, and which will be detailed below in the specification; alsovisible under the base are two V-shaped wheels surrounded by two slidepads, which will be detailed below in the specification, and to the leftof the base, a sliding contact element (used to supply power to thecarriage). A variant of FIG. 7 (not shown) will be to arrange theV-shaped wheels such that they surround the slide pads, which preferablymeans that the slides will be positioned on the fixed rail and theheight of the slide pads will be less than the V-shaped wheels under thebase of the carriage.

In a particular embodiment of the present invention, the carriage guidesystem thus comprises at least one rail connected to the carriagewheel(s) according to a V-guide device; this makes it possible to guidethe wheel(s) of the carriage in the Vs of the rail; preferably a railwith double V-guide for guiding the V-shaped wheels of the carriage.Thus, in a particular embodiment of the present invention, the carriageis provided with four V-shaped wheels (preferably symmetrically, two bytwo, relative to the center of the carriage), two of the wheels beingguided by the V on one side of the rail, and the other two wheels beingguided by the V on the other side of the rail.

In a particular embodiment of the present invention, the rail ispositioned centrally over the width of the base; thus, in an alternativeembodiment of the present invention, the center of the width of the railis at a distance of less than 20 cm, e.g., less than 15 cm from thecenter of the width of the base. In a particular embodiment of thepresent invention, the center of the width of the path of magnets isaligned with the center of the width of the fixed rail.

Thus, according to one feature of the present invention, at least aportion of the rail is fastened on a base or forms an integral part ofsaid base. A base could advantageously be used along the entire lengthof the rail for its fastening. However, as these bases and, inparticular the bases defined above, represent a load and a significantfinancial investment, it is also possible to provide any suitable typeof recessed rigid structure for fastening the rail—or for incorporatingthe rail into said structure—along the transport path; by way ofillustration, we mention a mechanically welded frame and/or a profiledframe. In a particular embodiment according to the present invention, arecessed rigid structure is used for fastening the rail (orincorporating the rail into the said structure) outside the printingand/or drying stations and/or any other substrate treatment station.Thus, in an alternative embodiment of the present invention, the totallength of the recessed rigid structure used for fastening the rail ofthe transport device is greater than or equal to halt the length of thetransport loop greater than or equal to 0.6 times the length of thetransport loop, e.g., greater than or equal to two thirds of the lengthof the transport loop.

Displacement Sensor

In a preferred embodiment of the present invention, the transport deviceis equipped with at least one displacement detection system (or sensor),preferably a linear displacement detection system (or sensor), formeasuring the displacement (position, speed, acceleration and/ordeceleration) of the carriage relative to the fixed rail. Anydisplacement detection system (or sensor) meeting the necessaryprecision requirements may advantageously be used in the deviceaccording to the present invention. By way of non-limiting illustration,we mention a displacement sensor comprising a mobile and a fixed part,e.g., an optical ruler. In a preferred embodiment of the presentinvention, the fixed part of the displacement sensor (e.g., the opticalruler) preferably consists of a linear ruler, preferably positionedalong the transport loop under the printing station and/or the dryingstations and/or any other substrate treatment station requiringincreased accuracy of measurements of the position, speed, accelerationand/or deceleration of the carriage along the transport loop, preferablyunder the printing stations. This (preferably linear) ruler maytherefore advantageously be an integral part of the rail and/or fastenedon the rail and/or on the base of the rail, and/or an integral part ofthe base of the rail, and/or fastened on the rail structure and/or anintegral part of the rail structure. The presence of the (preferablylinear) ruler thus makes it possible to determine, at any time, thepositioning, speed, acceleration and/or deceleration of the carriages onthe transport loop. In a preferred embodiment of the present invention,the carriage incorporates at least one reader (preferably an opticalreader), which forms the moving part of the displacement sensor.

FIG. 1 provides a schematic overview of the substrate-transport deviceaccording to the present invention. It shows the carousel-type substrateconveyor for guiding and moving the substrates, the said conveyorcomprising a fixed rail, which forms a closed transport loop, andcarriages that hold the substrates in a stationary (e.g., flat)position, and which move on the said rail while transporting thesubstrates, and allowing for the control of the displacement on accountof the linear ruler which, in this FIG. 1 , coincides with the fixedrail. FIG. 6 also schematically illustrates the ruler, which ispositioned in this configuration to the left of the optional holdingpart, which is fastened on the fixed rail.

In a preferred embodiment of the present invention, the transport deviceis equipped with at least one displacement sensor, preferably a lineardisplacement sensor, for measuring the displacement (position, speed,acceleration and/or deceleration) of the carriage relative to thetreatment station(s). Any displacement sensor meeting the necessaryprecision requirements may advantageously be used in the deviceaccording to the present invention, By way of non-limiting illustration,we mention a displacement sensor comprising a mobile and a fixed part,e.g., a magnetic optical ruler. In a preferred embodiment of the presentinvention, the moving part (“moving,” in the sense that it moves alongwith the carriage) of the displacement sensor (e.g., the magneticsensor) preferably consists of a linear ruler attached along alongitudinal axis (i.e., in the direction of travel of the carriage) onthe carriage or being an integral part of the carriage). The presence ofthe preferably linear ruler thus makes it possible to determine, at anygiven time, the positioning, speed, acceleration and/or deceleration ofthe carriages on the transport loop relative to the treatmentstation(s). In a preferred embodiment of the present invention, at leastone treatment station, preferably at least one printing station,preferably all the printing stations, or even all the treatmentstations, incorporate at least one reader (preferably a magneticreader), which forms the fixed part of the displacement sensor.

In a preferred embodiment of the present invention, the transport deviceis equipped with at least one “O” displacement sensor for measuring thedisplacement of the carriage relative to the rad, and at least one “M”displacement sensor for measuring the displacement of the carriagerelative to the treatment station. In a particular embodiment of thepresent invention, the “O” sensor reader and the “M” sensor ruler aresituated on the carriage. In a particular embodiment of the presentinvention, the ruler of the “O” sensor forms an integral part of therail, and/or is fastened on the rail, and/or is fastened on the base ofthe rail and/or forms an integral part of the rail base, and/or isfastened on the rail structure, and/or forms an integral part of therail structure. In a particular embodiment of the present invention, thetea “M” sensor reader is fastened on a fixed (or mobile) element of aprinting station and/or a drying station, and/or another treatmentstation. In a particular embodiment of the present invention, the “O”sensor is an optical linear displacement sensor and the “M” sensor is amagnetic linear displacement sensor. Indeed, the Applicant hasdiscovered that due to the combination of these two displacementsensors, an exceptional level of measurement accuracy (e.g., on theorder of one micrometer on the critical sections of the transport loop.e.g., in the micrometer range, on transport loop lengths in theone-meter range) could be achieved, thus allowing for optimally managingthe positioning and/or speed and/or acceleration and/or the decelerationof the carriages along the transport loop. The dual positioning controlof the readers/sensors, as described above, also adds other keyadvantages to the present invention, as described below. In fact, havingthe “O” sensor reader arranged on the carriage makes it possible toavoid any problems of transmitting the information measured between thereader and the active elements of the carriage, e.g. controlling theprimary motor assembly of the linear drive of the mobile carriage; thisresponsive control makes it possible to improve the intelligent and/orautonomous nature of the carriage by making it possible to minimize thedelays between the measurement and the corresponding induced action.Moreover, having the ruler of the “M” sensor arranged on the carriageand therefore the corresponding “M” sensor reader on a fixed (or mobile)element of a treatment station (e.g., a printing and/or drying and/oralternative treatment station) makes it possible to avoid any problemsof transmitting the measured information between the reader and theactive elements of the treatment station (e.g. a printing station (e.g.,the printheads of said printing station), and/or a drying and/oralternative treatment station) along the transport path. Thisresponsiveness allows the said station(s) to act without delay accordingto the performed measurement, i.e., it is possible to minimize thedelays between the measurement and the corresponding induced action;this responsiveness also makes it possible to avoid having aninformation exchange system between the carriage and the treatmentstation in order to obtain this positioning information, which, inaddition, reduces costs. Furthermore, the dual positioning control makesit possible to adjust the measurement elements to the requirement(s) ofthe carriage(s) and the treatment station(s) (e.g., a printing station).In fact, the Applicant has found that the measurement accuracy, and moreparticularly, the knowledge of the positioning of the movable part(e.g., the carriage), may vary between the carriage(s) and the treatmentstation(s). Thus, the measurement accuracy between the “O” sensor andthe “M” sensor may be different (lower or higher), or equal. In aparticular embodiment of the invention, the sensors may be selectedaccording to the requirements of the treatment station (or thecarriage), and may therefore differ from one workstation (or carriage)to another. This also allows for cost efficiencies. Indeed, since it ispossible to adjust the measurement system to the requirements of thecarriage(s) and/or the treatment station(s), the cost of the requiredparts is optimized.

Slide

In a preferred embodiment of the present invention, the transport devicealso comprises at least one slide, e.g., a slide arranged on each sideof the center fixed rail.

FIGS. 2, 6 and 7 schematically illustrate the components of theseslides, which, in this illustration and embodiment, consist of rails andguide elements (e.g., guide pads) fastened on the carriage; in FIGS. 2and 6 , the rails of the two slides are fastened on the base and placedon either side of the fixed rail; in FIG. 7 , the slide pads arearranged under the base of the carriage and surround the V-shaped wheelsof the guide system. Bear in mind that a variant of FIG. 7 (not shown)will be to arrange the V-shaped wheels such that they surround the padsof the slides, which preferably entails that the slide rails will bepositioned on the fixed rail and that the height of the slide pads willbe less than the height of the V-shaped wheels below the base of thecarriage; in this configuration, the use of a single slide rail ispossible, even if this is not a preferred variant according to thepresent invention.

Any type of slide may advantageously be used according to the presentinvention.

In a preferred embodiment of the present invention, the slide comprisesa rail, preferably two rails situated on each side of the mil(preferably centrally), which are either fastened on the base or form anintegral part of said base.

In an alternative embodiment of the present invention, the slidecomprises a rail, preferably two rails, which form an integral part ofthe fixed rail (preferably centrally), and/or are fastened on the fixedrail (preferably centrally), and/or are fastened on the base of thefixed rail (preferably centrally), and/or form an integral part of thebase of the fixed rail (preferably centrally), and/or are fastened onthe fixed rail structure (preferably centrally), and/or form an integralpart of the fixed rail structure (preferably centrally).

In a preferred embodiment of the present invention, the slide is smoothand preferably comprises one or more guiding elements on the carriage,(e.g., “female” elements), preferably at least two, e.g., at least four(as shown in FIG. 7 ), e.g., gliding pads,

In a preferred embodiment: of the present invention, the slide is adovetail slide.

In fact, without wishing to be limited by this explanation, theApplicant believes that the use of the central rail and its guidance incombination with the aforementioned slide not only meets therequirements of precise displacement of the carriage along the transportloop, but also allows for optimized motion through the curves of thetransport loop.

According to an alternative embodiment of the present invention, thelength of the slide rail(s) may be identical to the length of the fixedrail or the transport loop. However, and this represents a preferredembodiment of the present invention, the total length of this/theserail(s) will preferably be less than that of the fixed rail, because itwill be preferable not to place them in the turns formed by thetransport loop; we refer to total length of rail per slide, as the saidslide rail may in fact consist of several sections of rail along thetransport loop.

In a preferred embodiment of the present invention, the total length ofthe slide rail of the transport device is selected so as to cover theentire space below the printing stations of the transport loop, Moreparticularly, if the total length of the printing stations is the valueX, then the total length of the slide rail of the transport device willbe at least X, so as to ensure the desired flatness below the printingstations and meet the requirements for precise carriage displacementalong the transport loop. However, since the presence of this slide railis not essential outside the printing stations, the total length of theslide rail of the transport device will be limited, e.g., to values lessthan 3 times X, preferably less than 2 times X, e.g., less than 1.5times X, i.e., less than 1.2 times X.

In an alternative embodiment of the present invention, the total lengthof the slide rail of the transport device is less than the sum of thelengths of the linear parts of the transport loop, e.g., less than halfthe length of the transport loop, less than 0.4 times the length of thetransport loop, e.g., less than one-third of the length of the transportloop.

In an alternative embodiment of the present invention, when the totallength of the slide rail of the transport device is less than the lengthof the transport loop (and/or when the said rail consists of severalrail sections along the transport loop), the width of the initial end(the input in the direction of movement of the carriage) and/or thewidth of the tail end (the output in the direction of movement of thecarriage) of the said rail will advantageously be less than the averagewidth of the said rail; without wishing to be limited by thisexplanation, the Applicant believes that this makes it possible toensure optimal insertion (and/or exit) of the guiding element (e.g., ofthe pad(s)) into the rail, while limiting the mechanical wear, prematuredegradation of the rails, as well as vibration phenomena, which mayinterfere with the objectives of the present invention. For example, wemention by way of illustration a V-shaped input and/or an invertedV-shaped output for the slide rail of the transport device.

According to a preferred embodiment of the present invention, the systemfor guiding the carriage on the fixed rail comprises:

-   -   At least one pair of guide elements arranged on either side of        the rail (e.g., wheels), each pair of guide elements (e.g., a        pair or wheels) having a mechanism for guiding the carriage both        in straight sections and in turns, a support bar, which connects        the two guide elements with one another (e.g., the two wheels),        the said support bar comprising a pivoting axis connected to the        carriage in order to ensure optimal guidance of the carriage        along the rail and, in particular, along the turns formed by the        transport loop; and    -   At least one slide consisting of fixed rail(s) and guiding        elements, as described above, the said elements forming a slide        connection (for example pads) with the rail(s).

Carriage

A feature of the present invention is therefore the use of a substrateconveyor, preferably of the carousel type, for guiding and moving thesubstrates through treatment stations, the said conveyor comprising atleast one, preferably several carriages, which hold the substrates in astationary position (e.g., flat), and which move on a fixed rail, whichmakes it possible to move each carriage/substrate assembly on the rail,and characterized in that the said carriage comprises a table,preferably a suction table, holding the substrate in a stationaryposition (e.g., flat) relative to the table, along the transport loopduring substrate processing. FIG. 7 illustrates the carriage and some ofits components, e.g., a substrate support table, the V-shaped wheels ofthe guide system, as well as the slide pads, and an (electrical) slidingcontact element. The dimensions of the carriages and tables will beselected according to the requirements and applications, while allowingfor factors, such as bulkiness, weight and machining. By way ofnon-limiting illustration, we have designed carriages of the (W/L/H)dimensions 800/1250/3000 mm, including (holding) tables of the (W/L/H)dimensions 765/1075/1500 mm.

In an alternative embodiment of the present invention, the carriage isequipped with an identification means allowing for “personalization”during the passage of the carriage, i.e., identification by any stationof the device according to the present invention. The present inventionmay use any carriage-identification technology, preferably contactless.

By way of non-limiting illustration, this identification means mayadvantageously be selected from RFID (Radio FrequencyIdentification—technology for identifying objects, making it possible tostore and retrieve data remotely, using markers known as “radio tags”(or “transponders”)), harcodes, and/or any other technology based on therecognition principle, e.g., an optical transceiver.

By way of nonlimiting illustration, it would be possible to identify themaintenance carriage (e.g., the “inkjet, head-cleaning” carriageinserted into the stream of mobile carriages) and thus prevent it frombeing exposed to any substrate treatment whatsoever, and prevent theloading and/or unloading of the substrate onto this maintenancecarriage.

Table—Holding

According W an alternative embodiment of the present invention, any typeof preferably flat upper surface table, and any system for holding thesubstrate in a stationary position (e.g., flat) on the said table mayadvantageously be used. Thus, according to a particular embodiment ofthe present invention, the holding force exerted by the holding systemin the stationary position of the said substrate on the table will begreater than any other force that could cause the displacement of thesubstrate during the treatments of the said substrate and/or duringcarriage movements. As an illustration of a system for holding thesubstrate in a stationary (e.g., flat) position on the table, we mentionmeans for gripping or pressing the substrate, e.g., nippers and/ornipper strips. Thus, in order to meet the particular objectives of thepresent invention, the dimensions of the table will preferably meet thefollowing criteria: a transverse dimension (i.e., perpendicular to thelongitudinal axis in the plane of the transport path) at leastequivalent to the transverse size of the largest utilized substrate—anda longitudinal dimension at least equivalent to the longitudinaldimension of the largest utilized substrate: an additional advantage ofthe present invention is that several substrates (identical ordifferent) may be held in a stationary (e.g., flat) position on thetable, which demonstrates the exceptional flexibility provided by thedevice according to the present invention. The upper layer of thecarriage shown in FIG. 7 is a simplified schematic representation of thewhole holding table (front view). A representation of three identicalsubstrates held in a stationary position on a holding table isdescribed, for illustrative purposes, in FIG. 8 (top view).

Vacuum Table

A feature of a particular and preferred embodiment of the presentinvention is therefore the use as a holding table of a suction table,which forms part of the transport carriage and which makes it possibleto maintain the substrates in a stationary (e.g., flat) position alongthe transport loop. The suction tables and their operation are wellknown to those skilled in the art and they will therefore have noproblem using a suction table suitable for the present invention. Thestructure and dimensions of the suction table are not critical, providedit fulfills its purpose of holding the substrate in a stationary (e.g.,flat) position. Thus, according to a particular embodiment of thepresent invention, the holding force in the stationary position of saidsubstrate on the suction table will be greater than any other force thatcould cause the displacement of the substrate during the treatments ofsaid substrate and/or during the motions of the carriage by way ofnon-limiting illustration, we mention the potential influence of dryingby a heated air current upon the position of the substrate on thesuction table, an influence that must therefore be thwarted by theholding force of the suction table.

Suction Baseplate

The upper part of the suction tables is generally referred to as thesuction baseplate, which is usually made mostly of metal and/orpolytetrafluoroethylene (also known as Teflon) perforated by a multitudeof holes, allowing the table to perform suction and therefore holdingdue to this suction force of the substrate on the baseplate. In apreferred embodiment of the present invention, a baseplate of the typedescribed above is not used as illustrated below in the description ofthe figures.

Active Suction Area

The lower part of the suction tables generally consists of an activesuction area (active suction assembly). The suction tables and theiroperation are well known to those skilled in the art and they cantherefore easily use a suction table comprising an active suction areasuitable for the present invention, i.e., an active suction areasufficiently powerful to hold the substrate in a stationary position(e.g., flat) on the suction table. By way of illustration, an activearea of active suction is shown in FIG. 9 , which shows that the activesuction area comprises five suction units (represented in the figure byfans), which are preferably individually adjustable. Bear in mind thatit was already made clear that a major objective of the presentinvention is to prevent the components of the transport device fromcompromising the efficiency requirements of each of the printingstations and/or treatments. The same obviously applies to the suctiontable and, in the context of the present invention, we favor controlling(e.g., by varying the suction power), preferably controllingindividually, the constituent elements of the active suction area (ofthe active suction unit). For a better understanding of the presentspecification and the claims, we will characterize the active suctionassembly comprising at least two suction elements by using the term“compartmentalized.” Thus, in a preferred embodiment of the presentinvention, the active compartmentalized suction assembly (the activesuction area) will comprise at least two, preferably at least three,preferably at least four, e.g., at least five suction elements, whosepower may be controlled, preferably individually. A representation offive suction elements (five fans) is described for illustrative purposesin FIG. 9 (bottom view). The assembly formed by the active suction areais therefore an essential component of the suction table, the saidactive suction assembly preferably forming the lower layer of the table.In an alternative embodiment of the present invention, this activesuction assembly is attached to the passive layer situated immediatelyabove, e.g., by means of clamps; for illustrative purposes, this activesuction assembly may be incorporated in a frame, which is preferablyattached to the passive layer located immediately above, for example bymeans of clamps. In another alternative embodiment of the presentinvention, this active suction assembly is attached to the base of thecarriage or an intermediate element, which itself is attached to thebase of the carriage.

Passive Suction Area—Chambers

In a preferred embodiment of the present invention, the suction tablealso comprises a chambered structural layer (passive suctionarea/passive suction assembly) situated above the active suction area(between the active suction area and the substrate), which helps tocompartmentalize the suction flows. This structural layer is preferablyrigid or semi-rigid. For example, this structural layer compriseschambers Ch (or compartments Ch), which are preferably arranged oppositethe compartments of the suction area in order to improve the control ofthe power and/or homogenization of the suction within the chambers. Thedimensions of this structural chambered layer (passive suctionarea/passive suction assembly) are selected according to therequirements and applications; the widths/lengths of this structurallayer (e.g., a rectangular, parallelepiped-shaped flame of a height “h”)preferably coincide with those of the active suction layer; the heightsof this layer (and thus, preferably, also the chambers) are notcritical, as long as the layer fulfills its purpose or homogenizationand/or control of the suction power of the suction table; by way ofnonlimiting illustration, we mention a height “h” of this structurallayer (and thus, preferably also of the chambers) between 10 and 50 mm,e.g., between 15 and 30 mm, e.g., 20 mm. This structural layeradvantageously comprises at least two, preferably at least three,preferably at least four, e.g., at least five chambers. The number ofchambers may advantageously correspond to the number of compartments ofthe active suction area. However, and this represents a particularembodiment of the present invention, the structural layer is removable(e.g., by means of clamps), and may therefore be replaced, as needed;this will make it possible to use several chambers suitable for thesubstrates and/or treatments used without having to change thecompartmentalized active suction area. According to an alternativeembodiment of the present invention, the number of chambers will stayless than 20, preferably less than 10, in order to avoid bulkiness,which is likely to interfere with the performance of the suction area.

By way of illustration, a passive suction area is shown in 10, whichshows that the passive suction area comprises five chambers (illustratedin the figure by rectangles—top view); clamps are also visible on allfour sides of this frame.

Thus, according to a preferred embodiment of the present invention, theholding table is a suction table, which comprises an active suctionassembly, which, is compartmentalized into two or more suction elements(e.g., three, four, five, or more) surmounted by a passive suctionassembly, which is compartmentalized into two or more chambers (e.g.,three, four, five, or more), characterized in that the number andarrangement of the chambers preferably coincide with the suctionelements.

According to an alternative embodiment of the present invention, thesurface of the upper part of the chambers consists of one or moredual-purpose grids: these grids will impart a flat surface to the upperpart of the passive suction assembly, which will improve the flatpositioning of the next layer, and also help distribute the suctionflows within each chamber. Thus, a chamber will advantageously compriseon its upper surface at least five, preferably at: least ten, e.g., atleast 15 surface sub-chambers defined by the grid mesh. By way ofillustration, FIG. 11 describes a structural layer (passive suctionarea/passive suction assembly), which comprises five chambers, threechambers comprising 21 surface sub-chambers each, and two chamberscomprising 18 surface sub-chambers each.

In a preferred embodiment of the present invention, the chamberedstructural layer (passive suction area/passive suction assembly) alsocomprises additional suction-homogenization elements, elements that arepreferably situated in locations, where the positioning of the fans mayrisk causing suction peaks and/or swirls that could interfere with theproper operation of the treatment stations. By way of illustration, FIG.11 shows a structural layer (passive suction area/passive suctionassembly), which comprises five additional sue on-homogenization dementsin the form of pastilles (discs)) situated Opposite the center of thesuction elements of the active suction area, which makes it possible tomitigate any swirling effect and/or suction peak, which could generatesaid suction elements.

Thus, according to a particular embodiment of the present invention, thesuction table comprises an active suction assembly (active suctionarea), as defined above, in combination with a passive suction assembly(passive suction area), as defined above, so as to control the suctionpower of the table according to the positioning of the substrates; byway of illustration, this not only allows suction to be optimallybalanced, regardless of the position and size of the substrates, butalso makes it possible to limit the suction in specific sensitive areas,e.g., when the carriage passes through below the print heads.

Adjustable-Carriage

In a particular embodiment according to the present invention, a systemfor varying the height and/or orientation and/or a translation/rotationof the holding table (preferably the suction table) is incorporated inthe carriage, e.g., a drive system and/or jack(s). This additionalsystem (e.g., this drive and/or jacks) can be extremely useful, e.g.,making up for faulty print nozzles and/or increasing the resolution ofprints and/or ensuring optimal positioning of substrates below thetreatment stations. By way of non-limiting illustration, we mentionrotation and/or translational movement of the table allowing for the useof a nozzle to replace a faulty nozzle in order to perform printing at aprecise substrate location. By way of non-limiting illustration, a(transversal) micrometric drive for this type of drive is used;displacements may therefore advantageously reach a precision on theorder of μm's, and will preferably be limited to maximum valuesequivalent to cm's in the three dimensions of space.

By way of non-limiting illustration, FIG. 7 illustrates the presence ofthis element comprising an additional drive; a carriage comprising astructural base is clearly visible in light gray in the figuresurmounted by a (dark gray) holding table, including an intermediatemember between the table and the base forming this additional driveelement, e.g., a micrometric drive for moving the table in a directionperpendicular to the direction of travel of the carriage.

Honeycomb Layer

During the development and enhancements performed on the transportdevice of the present invention, the Applicant also determined that thesurface temperature of the substrate and thus the surface temperature ofthe upper part of the holding table had a not negligible effect on thequality of the prints (and, in particular, the quality ofprinted-electronics prints), as well as the performance of the dryingstations. Thus, in a preferred embodiment of the present invention, thetable (preferably the suction table) comprises a structural honeycomblayer. The Applicant, in fact, developed this particular embodiment ofthe invention, because the structural honeycomb layer makes it possibleto homogenize the surface temperature, as well as improve dissipation ofthe said temperature throughout the table. What's more, this honeycombstructural layer has several additional features/advantages, which wemention by way of non-limiting illustration:

-   -   An upper surface that is sufficiently flat for holding the        substrate in position;    -   Allows for the passage of air in order to create a depression        behind the substrate thereby ensuring optimal holding for the        suction-table option;    -   Limiting the effects of substrate thermal conduction, on account        of its slight contact surface;    -   Limiting the effects of thermal conduction with the lower and        upper layers of the table (which has proven especially        appropriate for certain treatment stations, e.g., infra-red        drying stations);    -   Contributing to the elimination of vibration problems found in        prior-art transport devices,

thus, making it possible to improve the transport of printable and/orprinted substrates on all of the treatment stations included in aprinting machine, in particular, a printing machine without contact withthe substrate, such as inkjet printing machines.

Furthermore, according, to a particular embodiment of the presentinvention, the claimed device and method differ from the prior art dueto their flexibility of use and a reduction of the manufacturing time,as well as of related costs, which makes them particularly attractive,particularly for printed electronics, e.g., the manufacture of printedcircuits. Thus, the present invention and its claimed suction table,with its described features, here we mention by way of example thestructural honeycomb layer, the optional lattice and the absence ofbaseplates with a multitude of holes, provide very important advantagesin the field of printed electronics printing. In fact, the Applicantnoted a major improvement in the printing quality and accuracy, as thesuction table has a dual beneficial action not only on printing, butalso on the drying of the printed ink, which opens up new areas for thepresent invention, such as printed electronics and, in particular,printed electronics with a radio frequency identification (RFD) tag,with or without a chip (also referred to as RFID tags or RFID tagswithout a chip); without wishing to be limited by this explanation, theApplicant believes that during the drying of the printed electronics,e.g., during infrared (IR) and/or near-infrared (NIR) treatment, thelocalized effect of the treatment combined with the effect or heatdissipation through the table allow for better annealing of the ink,which may, e.g., result in improved conductivity. The suction table alsomakes it possible to better adjust (depending on the substrate and theprinting/deposit application) the power and rate of drying. In addition,the suction table allows for heat dissipation, which limits thedeformations of certain substrates, i.e., no repercussions among thedifferent treatment stations (e.g., infrared (IR) drying withultraviolet (UV) drying).

By way of non-limiting illustration, the structural honeycomb layer hasa thickness “e” between 1 and 100 mm, between 5 and 30 mm, preferablybetween 5 and 15 mm, e.g., 8 mm; the size of the chambers (e.g., cells)is between 10 μm and 10 mm, e.g., between 1 and 8 mm, preferably between2 and 5 mm, e.g., 3.6 mm; the thickness of the chamber walls (e.g., thecells) is between 0.5 μm and 5 mm, e.g., between 10 and 200 microns,preferably between 30 and 100 μm, e.g., 50 μm.

By way of non-limiting illustration, the honeycomb structural layer is aregular hexagonal pattern, as shown in FIG. 12 ; it therefore consistsof hexagonal right prisms (which therefore preferably do not includeholes in their vertical walls).

The surface dimensions of the structural honeycomb layer are selectedaccording to the requirements and applications, and preferablycorrespond to at least the surface of the substrate (or substrates, ifmore than one is held on the same table); we mention for illustrativepurposes the (W/L) dimensions in mm on the order of 760/1070. Thewidths/lengths of this structural layer of the honeycomb type (e.g., aframe of a rectangular parallelepiped shape of a height corresponding,to the thickness “t.” mentioned above) preferably coincides with thoseof the passive suction layer, and preferably also with those of theactive suction layer.

Thus, according to a particular embodiment of the present invention, thetable (preferably the suction table) comprises a structural layer of thehoneycomb type, as defined above. The use of this structural layer ofthe honeycomb type in the table (preferably the suction table) has madeit possible to solve other basic problems found in the prior-artdevices. In fact, inkjet printing techniques (whether via a conventionalor special ink printing station (e.g., conductive) and/or a varnishprinting station) often require rapid drying of the ink (or varnish),which explains why at least one drying station immediately follows aprinting station, along the substrate transport path. This closearrangement is unfortunately not very compatible with the properfunctioning of the print heads, as close drying may impact theperformance of said heads, e.g., by a blocking effect of theprinting-nozzles, as a result of unintentional solidification of the inkin these nozzles. Thus, the prior-art techniques made it necessaryeither to move the drying station away from the printing station at therisk of harming the print-rendering quality, or strictly control drying,e.g., by decreasing the drying power at the risk of having todrastically restrict the printing rates, as well as harming theprint-rendering quality. These problems are even more acute in the fieldof printed electronics. Thus, the Applicant has discovered that the useof a structural honeycomb layer (as described above) in the table(preferably the suction table) alleviates these prior-art problems,which represents a considerable advantage of the transport deviceaccording to the present invention. In fact, without wishing to belimited by this explanation, the Applicant believes that the use of astructural honeycomb layer (as described above) allows for optimaldissipation of the heat generated by the drying station, as well as adrastic reduction of the thermal reflection and transfer phenomena hithe table and/or from the table to the printheads; by way of nonlimitingillustration, the applicant believes that the use of a structuralhoneycomb layer (as so described above) allows for, e.g., trapping theUV radiation from the drying so that it does not interfere (by way ofreflection) with the proper operation of the printheads and thus do notcause hardening of the ink within the print nozzles. In addition, andthis constitutes another advantage according to the present invention,the use of a structural honeycomb layer (as described above) makes itpossible to dispense with the prior-art suction soles, such as, e.g.,those described above (baseplates usually made mainly of metal and/orpolytetrafluoroethylene (also known as Teflon) and perforated by amultitude of holes); indeed, the structural layer of the honeycomb type(as described above) may serve directly as a support baseplate fir thesubstrates and thus allow the table to perform suction and thus holdingthe said substrates on this baseplate.

In a particular embodiment of the present invention, the structuralhoneycomb layer is removably attached to the table, which allows it tobe replaced and/or changed depending on, for example, the types ofsubstrates used. Any removable fastening system may advantageously beused; by way of illustration, we mention a fastening of the frog-legand/or clipsable type.

According to an alternative embodiment of the present invention, thestructural honeycomb layer is made of aluminum; it is obvious that thoseskilled in the art will be able to select other materials, whether ornot similar to aluminum, which also meet the requirements of the presentinvention, e.g., steel and/or any plastic material and/or compositeand/or suitable ceramic.

According to an alternative embodiment of the present invention, thestructural honeycomb layer is not sandwiched, i.e., does not include alower and/or higher sublayer; this variant is preferred in the case of asuction table in order to not to interfere with the suction through thechambers (e.g., cells).

Lattice

In a particular embodiment of the present invention, the table(preferably the suction table) comprises a structural layer consistingof a lattice for holding the substrates. By way of non-limitingillustration, this lattice may advantageously be used for substrates oflow basis weight, which makes it possible to avoid any possible“labeling,” of the said substrates during their immobilization on thetable. In fact, without wishing to be limited by this explanation, theApplicant believes that the use of a lattice for holding the substratesalso makes it possible to freeze and keep the honeycomb layer in itsoriginal form while, in the utilization embodiment of the suction table,ensuring and improving suction homogenization.

By way of non-limiting illustration, a holding lattice is illustrated inFIG. 13 .

By way of non-limiting illustration, a grid of stainless steel and/orceramic fiber may advantageously be used as a lattice. It is obviousthat those skilled in the art will be able to select other materials,whether similar or not to stainless steel and/or ceramic fibers, whichalso meet the requirements of the present invention.

By way of non-limiting illustration, the lattice mesh is selected fromfine meshes in order to avoid texturing of the printed paper.

By way of non-limiting illustration, the dimensions of a lattice meshwill be less than half the size of the honeycomb cell, e.g., less than aquarter of the size of the honeycomb.

By way of non-Limiting illustration, the lattice leas

-   -   A thickness of between 1 μm and 1 mm, preferably between 10 and        500 μm, e.g., between 25 and 300 μm; and/or    -   A mesh network (square, triangular rectangle, hexagonal or        other), where the greatest length of one side of the mesh is        between 1 μm and 1 mm, preferably between 50 and 500 μm, e.g.,        between 75 and 300 μm; and/or    -   A wire diameter of between 1 μm and 1 mm, preferably between 10        and 200 μm, e.g., between 25 and 150 μm.

The surface dimensions of the structural lattice layer will be selectedaccording to the requirements and applications, and will preferablycorrespond to the surface of the substrate (or substrates, if more thanone is held on the same table), plus a safety margin; for illustrativepurposes, dimensions (W/L) are stated in mm on the order of 760/1070.The widths/lengths of this lattice will preferably coincide with thoseof the structural honeycomb layer, and optionally with those of thepassive suction layer, and optionally also with those of the activesuction layer.

The lattice preferably consists of a network of regular and/or identicalmeshes.

The combination of a lattice, as defined above, attached to thestructural layer of the honeycomb type (as described above) is apreferred embodiment of the present invention for holding the substrateson the table (preferably the suction table). Indeed, the use of astructural layer of the honeycomb type (as described above) and alattice makes it possible to do without the prior-art suctionbaseplates, such as, e.g., those described above (baseplates usuallymade predominantly of metal and/or polytetrafluoroethylene (also knownas Teflon) and perforated by a multitude of holes); in fact, thestructural layer at the honeycomb type (as described above), upon whicha lattice is deposited/attached may serve directly as a supportbaseplate for the substrates and thus allow the table to perform suctionand hold the said substrates on this baseplate.

In a particular embodiment of the present invention, the lattice isremovably attached to the table, which allows for its replacement and/orexchange according to, e.g., the types of substrates used. Any removablefastening system may advantageously be used; by way of illustration, wemention a fastening of the frog-leg and/or clip fable type. In analternative embodiment, the removable fastening system fastens the meshdirectly on the honeycomb layer.

According to an alternative embodiment of the present invention,optional masking areas may be added to the lattice, e.g., to preventaspiration into areas without a substrate.

Filter Layer

In a particular embodiment of the present invention, the table(preferably the suction table) comprises an additional optional layerconsisting of a filter, which makes it possible to further improve theefficiency of the table by making it possible to trap the rays, whileavoiding their reflection on the table, By way of non-limitingillustration, this filter is an anti-UV filter.

The surface dimensions of the filter layer are selected according to therequirements and applications, and will preferably correspond to thesurface of the substrate (or substrates, if more than one is held on thesame table), plus a safety margin; by way of illustration, (W/L)dimensions are stated in mm on the order of 760/1070. The widths/lengthsof this filter preferably coincide with those of the lattice and/orstructural honeycomb layer, and optionally with those of the passivesuction layer, and optionally also with those of the active suctionlayer.

In an alternative embodiment of the present invention, this filter layeris placed directly below and/or above the honeycomb layer and/or thelattice.

Flatness Sublayer

It is possible that height deviations will occur between certain pointsof the surface of the above-mentioned layers in the table, such that thesaid deviations create height differences, which m some places may reachan order of magnitude of tens(s), or even hundred(s) of μm's. It ispreferable that these deviations be prevented from compromising thequality and/or performance of the treatment stations (especially theprinting stations). Moreover, in case of major deviations, there relaybe a risk of contact between certain points of the upper layer of thetable and the treatment station, e.g., the printheads, which then riskbeing damaged.

Thus, in a particular embodiment of the present invention, the table(preferably the suction table) comprises additional optional elements(which we will refer to as sub-layer flatness elements) arranged inprecise locations between two of the above-mentioned layers, making itpossible to improve the homogeneity/flatness of the table supporting thesubstrate(s).

This additional optional sublayer thus allows for levelling the layerssituated above and/or below it, and making the last layer of the tableflat.

By way of nonlimiting illustration, this flatness sublayer comprisesmetal plates of aluminum), which, for illustrative purposes, may bearranged:

-   -   Either between the active suction assembly and the passive        suction assembly (chambered structural layer);    -   Or between the passive suction assembly (chambered structural        layer) and the honeycomb layer.        Carriage Structure, Etc.

FIG. 7 thus illustrates a variant of the carriage according to theresent invention, said carriage comprising a structural base shown inlight gray and surmounted by a table (in dark gray) for supporting thesubstrates, V-shaped wheels below the base (for the fixed V-guide rail)and slide pads; this FIG. 7 also schematically illustrates a conductivecontact element (sliding electrical contact), which ensures theelectrical connection between the conductor rail (described below andthe carriage.

In summary, and not necessarily illustrated in the figures, the carriageaccording to the present invention advantageously comprises thefollowing:

-   -   A structural frame, preferably of aluminum, said frame being        able to act as a base for the carriage; and/or    -   An element of the guide system, e.g., an element of the V-guide        system (e.g., the V-shaped wheels); and/or    -   An element of the slide(s), e.g., the sliding element (e.g., the        pad(s)); and/or    -   A control element for the carriage, e.g., a programmable        controller; and/or    -   A drive system for orienting the table in the three dimensions        of space; and/or    -   A holding table; and/or    -   A suction table; and/or    -   An active suction assembly; and/or    -   A passive suction assembly; and/or    -   A honeycomb layer; and/or    -   A lattice; and/or    -   A filter layer; and/or    -   A flatness sublayer; and/or    -   Displacement sensor elements; and/or    -   Carriage protection elements, as described below.

In a particular embodiment of the present invention, the carriage alsoincludes a substrate-lifting device. Indeed, in certain situations and,in particular in the field of printed electronics printing, it isnecessary to use a particular system for feeding and removing thesubstrates to be treated, the said system making it necessary toincorporate in the carriage an autonomous device for lifting thesubstrates. Any autonomous lifting device may advantageously be used;for illustrative purposes, we mention a device comprising jacks arrangedon the carriage, e.g., arranged in the table. Thus, this device makes itpossible

-   -   To receive the substrates to be treated at a sufficient        elevation above the table, while supplying the substrate to be        treated; and    -   To position the said ted substrates at a sufficient elevation        above the table,        the elevation being dictated by the particular substrate feeding        and removal system,        Carriage Protection

In a particular embodiment of the present invention, the carriagestructure comprises at least one protection, which makes it possible toavoid damaging the other components of the carriage in the event of anaccidental collision between two carriages. This protection willtherefore ideally be placed on the front or rear edge (seen in thedirection of travel) of the carriage or, preferably, on the front andrear edges of the carriage. As the device according to the presentinvention makes it possible to control each of the carriagesindividually and thus precisely know their positions and speeds, theseprotections are not required. However, in order to mitigate thepotential risks related, e.g., to a power failure and/or a failurerelated to data transmission (instructions) to the carriage, this typeof protection is given preference. Any protection to minimize and/oreliminate problems that could have an impact on the carriages mayadvantageously be used in the context of the present invention; by wayof non-limiting illustration, we mention impact protection of theshock-absorption type, either using springs or through defamation.

Siding—Bypass

An optional feature of the substrate-transport device of the presentinvention is thus the use of a carousel-type substrate conveyor forguiding and moving the substrates through the treatment stations, thesaid conveyor comprising carriages, which hold the substrates in astationary (e.g., flat) position and which move on a fixed rail, whichforms a transport loop, characterized in that the device comprises asiding for the carriages, the said siding being releasably connected tothe conveyor rail and thus allowing for adding and/or removing one ormore carriages. By way of non-limiting illustration, this type of sidingis similar to what is used in the rail sector, a switch to divertcertain trains and/or freight cars. By way of non-limiting illustration,the carriage may be conveyed by perpendicular translation to thetransport loop toward the said siding by means of any other appropriatedevice. This siding may advantageously from a dead end and/or a bypassloop on the transport loop, and be located at any suitable location ofthe transport loop, with an identical and or different entry and exitpoint of the loop.

Moreover, this siding is very useful, as it allows any maintenanceaction on the carriages; we mention by way of non-limiting illustration;

-   -   The maintenance and/or replacement of one or more table        components, as described above. e.g., the protection and/or the        lattice and/or the honeycomb layer and/or an active suction        element (e.g., a fan);    -   Maintenance and/or replacement of one or more components of the        active part (or the passive part, depending on the        configuration) of the linear drive;    -   Maintenance and/or replacement of one or more components of the        displacement sensors;    -   The addition and/or removal of carriage(s) in the transport.

Thus, an optional feature of the substrate-transport device of thepresent: invention is the use of a carousel-type substrate conveyor forguiding and moving the substrates through the treatment stations, saidconveyor comprising carriages, which hold the substrates in a stationary(e.g., flat) position and which move on a fixed rail, which forms atransport loop, characterized in that the device comprises a bypass pathfor the carriages, the said path being removably connected to theconveyor mil and thus making it possible to provide any type ofadditional treatment of the substrate. By way of non-limitingillustration, we mention a process of reversing the substrate on thetable and/or a coating station, often referred to as a gilding station(“foil”), as described above in the specification; however, it should benoted that these treatments and/or processes could also take place inthe main transport loop. This bypass route may advantageously form abypass loop in the transport loop, and be situated at any suitablelocation of the transport loop, with an identical and/or advantageouslydifferent point of entry and exit in the loop; e.g., fora substratereversal process, a bypass loop may advantageously be arranged betweenthe substrate loading and unloading stations.

Maintenance Tray

In a particular embodiment of the present invention, thesubstrate-transport device comprises at least one carriage provided witha maintenance tray (e.g., a cleaning tray and/or an adjustment tray).This maintenance carriage (e.g., “cleaning” and/or “adjustment”carriage) may advantageously be in idle mode on a siding, as definedabove, and subsequently brought into active mode in the transport loopin order to perform any maintenance action required for the properoperation of the treatment stations. This cleaning and/or adjustmentcarriage is very useful, as it allows for performing, any maintenanceaction on the treatment stations; we mention for illustrative andnon-limiting purposes:

-   -   The maintenance and/or replacement of one or more components of        the treatment stations, e.g., cleaning of the printing nozzles,        etc.    -   Any adjustment action of the treatment station components.        Diagnostic Tray

In a particular embodiment of the present invention, thesubstrate-transport device comprises at least one carriage equipped witha diagnostic tray. This diagnostic carriage may advantageously be inidle mode on a siding, as defined above, and subsequently placed inactive mode on the transport loop in order to perform any diagnosticaction in order to verify the proper operation of the treatmentstations.

By way of non-limiting illustration, we mention an analysis of theprintheads.

In an alternative embodiment of the present invention, a carriage maycomprise both a diagnostic tray and a maintenance tray.

Data & Energy—Equipment & Management

A feature of the present invention is therefore the use of a substrateconveyor (preferably of the carousel type) for guiding and moving, thesubstrates through the treatment stations, the said conveyor comprisingcarriages, which hold the substrates in at stationary (e.g., flat)position, and which move on a fixed rail, which makes it possible tomove each carriage/substrate on the rail.

The part of the claimed device (with the exception of the carriage)allowing for supervision and/or control of the different elements of thesaid machine represents the “management component of the printingmachine.” By way of non-limiting illustration, the management componentof the printing machine may comprise the communication portion forexchanging information between the different elements of the machineand/or with the carriages. By way of non-limiting illustration, thisinformation consists of commands, instructions, positions, speeds, ID'sor any other useful information to be exchanged between the differentelements of the machine and/or the carriages. The management componentof the printing machine may contain the command means for differentactuators, such as the control means for the treatment stations. Themanagement component may also involve the management of differentsensors (e.g., a sensor arranged on the transport loop and/or in thetreatment suctions, e.g., positioning sensor(s)). The Managementcomponent may include management of the effectors. An effector finalizesthe work; it produces the expected effect. The management component mayalso contain interfaces, such as indicator lights, a screen, a means ofidentification, and any other interfacing means. Indeed, the Applicantdoes not wish to be limited to human-machine interfaces. It is quiteconceivable to have a machine-machine interface. By way of non-limitingillustration, a machine-machine interface may be an element of atreatment station (such as a barcode) allowing the carriages to identifythe treatment station and act accordingly. Of course, the Applicant doesnot wish to be limited solely to the elements mentioned above. It isobvious to those skilled in the art that programmable controllers,electronic circuits (which may contain FPGAs [Field Programmable GateArrays], and/or microprocessors), etc., may be included in themanagement component of the printing machine.

In a preferred embodiment of the present invention, thesubstrate-transport carriage may therefore travel autonomously along thetransport loop by means of an active motor element ensuring itsdisplacement, e.g., the linear motor described above (intelligent and/orautonomous carriage). This embodiment involves the need to supply themobile carriage with energy and ensure the transfer of information,preferably the bidirectional transfer of information (digitalinformation preferences). In a preferred embodiment of the presentinvention, this power supply will be permanent; however, standby periodswill be tolerated, when the carriage is located in an area, where it canremain stationary and/or without the need for information transfer.

The “carriage management component” represents the part of the carriagethat supervises and/or controls the different elements of the carriage.As a non-limiting illustration, the management portion of the carriagemay include the communication portion for exchanging information withthe rest of the machine. By way of non-limiting illustration, thisinformation are commands, instructions, positions, speeds, ID's or anyother useful information to be exchanged between the carriage and therest of the machine. The carriage management component may contain thecontrol means for different actuators, such as control means for theprimary motor assembly. The management component may also involve themanagement of different sensors (e.g., a sensor contained in thecarriage, such as positioning sensor(s)). The management component mayinclude effector management. An effector finalizes the work; it producesthe expected effect. The management component may also containinterfaces such as indicator lights, a screen, a means ofidentification, and any other interfacing means. In fact, the Applicantdoes not wish to be limited to human-machine interfaces. It is quiteconceivable to have a machine-machine interface. By way of non-limitingillustration, it machine-machine interface may be a carriage element(such as a barcode) allowing other treatment stations to identify thiscarriage and act accordingly. The carriage management component may beconsidered a part of the carriage rendering the carriage intelligentand/or autonomous. Naturally, the Applicant does not wish to be limitedsolely to the elements mentioned above. It is obvious to those skilledin the art that programmable logic controllers electronic circuits(which may contain FPGAs, and/or microprocessors), etc . . . , may beincluded in the management component of the carriage. By way ofnon-limiting illustration, the management component may also includeenergy regulation means.

Any energy supply solution for the mobile carriage may advantageously beused in the context of the present invention. In a preferred embodimentof the present invention, the power supply of the (intelligent and/orautonomous) mobile carriage will be sufficient to provide electricity to

-   -   The primary motor assembly of the linear drive of the carriage;        and optionally    -   The carriage management component; and/or    -   The suction table; and/or    -   The displacement detection system (or sensor) on the carriage.

The following are purely illustrative and not limiting power suppliesfor the battery, cell, solar panel, power generator (e.g., viagasoline), mechanical movement (e.g., via a weight-winding mechanism),automatic movement, and dynamo type, etc . . . in a preferred embodimentaccording to the present invention, the power supply of the mobilecarriage comprises a set of electrically conductive rails, which arepreferably fastened along the transport path and a sliding contactelement, which is preferably movable and fastened on the carriage. Byway of non-limiting illustration, FIGS. 1 and 6 show the said conductiverails; along the transport loop in FIG. 1 and on the left part in FIG. 6, as already described above. FIG. 6 shows how the power supply systemis fastened on the baseplate; in FIG. 1 , it is fastened over the wholelength of the baseplate and subsequently on the supporting structure ofthe (lightened/recessed) transport device according to the presentinvention. By way of non-limiting illustration, FIG. 7 shows on theleft, a type of comb corresponding to a simplified representation of thesliding contact element for supplying energy to the carriage.

Any solution for transferring information from/to the mobile carriagemay advantageously be used in the context of the present invention. In apreferred embodiment of the present invention, a radiating cable systemis used. For non-limiting and illustrative purposes, FIG. 6 shows theradiating cable to the left on the figure; in this illustration, it isplaced above the conductor rails.

Conductor Rails

In an alternative embodiment of the present invention, the set ofconducting rails (e.g., of the “third-rail” type) ensures (possiblybidirectional) transmission:

1. of (Electrical) energy supplying the active motor element for thecarriage and computer control means for the transport device; and/or

2. of electrical safety signals (global emergency stop and individualerror signals for each mobile carriage) ensuring that the whole mobilecarriages come to a stop in the event of a fault, e.g., in the event ofa fault of one or more carriages and/or in case of a defect in otherelements of the transport device and/or the printing machine; and/or

3. of electrical signals allowing the precise synchronization of themobile carriages with each other and/or a centralized computer controlmeans.

For illustrative purposes, this precise synchronization may be obtainedby using:

-   -   A centralized clock; and/or    -   Centralized cycle start/stop signals.

By way of illustration, this precise synchronization not only allows foroptimizing the movement cycle times of the carriages and thus thetreatment of the substrates; but also, in certain particular embodimentsof the present invention, for organizing simultaneous stops of twocarriages for loading and unloading their substrate(s).

Sliding Contacts

In a preferred embodiment of the present invention, the power supply ofthe mobile carriage thus comprises at least one sliding contact elementfastened on the carriage, the said contact sliding on the set ofconductive rails described above. By way of non-limiting illustration,FIG. 7 shows to the left on the figure, a type of comb corresponding toa simplified representation of the sliding contact element for supplyingthe carriage with energy, said contact befog fastened on the carriagestructure. In a preferred embodiment of the present invention, eachmobile carriage is equipped with several sliding contacts on the set ofconductive rails, said sliding contacts forming an assembly fastened oneach carriage.

Each carriage is thus continuously supplied and synchronized throughoutthe transport carousel, without having to be connected by means ofcables to a centralized power supply system, something which representsa considerable advantage of the power supply system of the transportdevice according to the present invention.

Wireless Communication

Thus, in a preferred embodiment of the present invention, the substratetransport carriage may therefore move autonomously along the transportloop, which makes it necessary to ensure the transfer of information tothe carriage, preferably the bidirectional transfer of information tofrom the carriage (preferably digital information).

As already indicated, any solution related to the transfer, preferablybi-directional transfer, of contactless information to/from the mobilecarriage may advantageously be used in the context of the presentinvention, such as, e.g., a system for radio transmission ofinformation, as shown in FIG. 6 , in particular, a radiating cable.

In a preferred embodiment of the present invention, the informationsupply for the mobile carriage is done contactlessly, e.g., by using theaforementioned radiating cable.

In a preferred embodiment of the present invention, the Applicantdeveloped a contactless communication system for the transfer,preferably bidirectional transfer, of information to/from the carriage.By way of illustration, we mention the option of radio waves, whosetransmission is ensured by technology selected from

-   -   A radiating cable; and/or    -   A waveguide; and/or    -   Antennas.

In a preferred embodiment of the present invention, the preferredcontactless communication solution for transferring information toand/or from the mobile carriage comprises a fixed radiating cable alongthe transport loop for the transmission of radio waves in communicationwith at least one radio-wave-receiving antenna placed on each of thecarriages.

This type of contactless communication allows, by way of illustration,for configuration of the carriage motion cycle, the said configurationbeing acquired from a computer control means.

By way of illustration, the means of communication selected forcustomization is a wireless communication via an electromagneticradiating cable placed along the whole carousel.

Any wireless information transmission technology between the mobilecarriage and the fixed part of the device according to the presentinvention may advantageously be used, By way of illustration, we mentionLTE and/or LTE-advanced technology (standards derived from current(3G/4G) and future generations of mobile telephony), and/or WiMAXtechnology (acronym for Worldwide Interoperability for MicrowaveAccess), and/or or Wi-Fi technology (abbreviation for WirelessFidelity), and/or femtocell technology, and/or Bluetooth wirelesstechnology, and/or DECT (acronym for Digital Enhanced CordlessTelecommunication).

In an alternative embodiment of the present invention, the transmissionof the wireless information between the mobile carriage and the fixedpart of the device according to the present invention may advantageouslybe carried out by means of the Li-Fi (“light fidelity”) technology,using the principle of transmission of information by light, e.g., bymodulating the light transmission very rapidly; any type of adaptedcurrent or future lamps may advantageously be used (e.g., LED lamps).

In an alternative embodiment of the present invention, the transfer ofwireless information between the mobile carriage and the fixed part ofthe device according to the present invention may also be done by meansof laser technology.

In an alternative embodiment of the present invention, the(bidirectional) transfer technology for the contactless informationbetween the mobile carriage and the fixed part of the transport device(e.g., the radiating cable) will be based on a so-called“short-distance” solution in order to avoid the risk of interferencewith the immediate environment for the transport device; forillustrative and non-limiting purposes, we mention Near FieldCommunication (“NFC”) technology.

In a preferred embodiment of the present invention, the preferredcontactless communication solution for transferring information from thetransport loop to the carriages comprises an information transmissionmeans, i.e., a fixed element along the transport loop (e.g., a radiatingcable) and, on each mobile carriage, a means for receiving saidinformation, i.e., a movable element fastened on each of the carriages(e.g., an antenna), an element preferably coupled electromagnetically tothe above-mentioned fixed element along the loop (preferably a radiatingcable). This solution is of interest, in that:

-   -   It has a limited radiating field near the cable and thus        generates few electromagnetic interferences; and/or    -   It is immune to electromagnetic interferences, which may be        generated by the external environment and/or the mobile carriage        itself due to the possible use of an electromagnetic        displacement means (a linear motor, etc.).

In a preferred embodiment of the present invention, the informationcommunication is bidirectional. In this embodiment, the preferredbidirectional communication solution comprises a means for informationtransmission and reception, i.e., a fixed element along the transportloop a radiating cable) and, on each mobile carriage, a means forreceiving and transmitting information (e.g., an antenna), an elementpreferably coupled electro-magnetically to the above-mentioned fixedelement along the loop (preferably a radiating cable). This solution hasthe advantage, in addition to customization, to allow for informationfeedback from each of the mobile carriages to the “control-means”software of the claimed device, e.g., information relating to themovements of the carriage (speed, position, acceleration, deceleration)and/or relating to various and sundry statuses (e.g., error messages,information from sensors, etc.). The preferably bidirectionaltransmission of information between, the control means (e.g., acomputer) and the means for transmitting and receiving information fromthe claimed device (e.g., the fixed element along the transport loop,preferably the radiating cable) may be wired and or contactless, usingany of the aforementioned contactless technologies.

Carriage Detection Sensor

In a preferred embodiment of the present invention, the claimed devicefurthermore comprises a set of sensors and protections ensuring thedisplacement safety of the mobile carriages, e.g., distance sensors. Byway of illustration, we mention the presence on the carriages of adistance sensor for detecting the carriage, which precedes it along thetransport path and/or a distance sensor for detecting the carriage,which follows it along the transport path; thus, each carriage maymanage in an autonomous fashion its position relative to the othercarriages and adapt its position, and/or its speed, and/or itsdeceleration and/or its acceleration.

Any type of position-detection sensor may advantageously be used in thecontext of the present invention; by way of non-limiting illustration,laser sensors will be preferred. The use of the said sensors will alloweach carriage:

-   -   To be independent and thus ensure its autonomy;    -   To avoid collision with the carriages situated ahead and/or        behind, and thus ensure compliance with operations        (acceleration, continuous speeds, etc.)

In an alternative embodiment of the present invention, each carriagecomprises at least one detection sensor, as described above, the saidsensor being positioned at any suitable location on the front and/orrear edge of the carriage (in the sliding direction of the carriage),e.g., at the center of the edge.

In a particular embodiment of the present invention, each carriagecomprises at least one detection sensor, as described above, said sensorbeing positioned on the front and/or rear edge of the carriage (in thesliding direction of the carriage), and characterized in that itsposition on the edge of the carriage is located proximate to and/or atthe external corner of the edge (the term “external” is used in relationto the rotation around the loop); e.g., for a carriage whose (front orrear) edge is of a length X, the sensor will be arranged on the (frontor rear) edge, at a distance from the outer corner below X/2, below X/4,of preferably below X/8.

In a preferred embodiment of the present invention, each carriagecomprises at least one detection sensor, as described above, on the fontedge of the carriage, and at least one detection sensor, as describedabove, on the rear edge of the carriage.

In an alternative, embodiment of the present invention, the wave emittedby the sensor positioned at the front rear edge of a carriage forms anyappropriate angle relative to the said front/rear edge of the carriage,e.g., a 90-degree angle.

In a particular embodiment of the present invention, the wave emitted bythe sensor positioned at the front/rear edge of a carriage forms anangle relative to the said front/rear edge of the carriage between 30and 90 degrees, e.g., less than 90 degrees, between 35 and 55 degrees,e.g., between 40 and 50 degrees, e.g., on the order of 45 degrees.

Furthermore the present invention relates to the use of the deviceand/or the method of transporting substrates according to any of theabove-described embodiments in a printing machine, comprising at leasttwo different in-series, contactless printing stations (preferablydigital inkjet printing), and at least one drying station along thetransport path; and, in particular, the said use in a printing machinefurthermore comprises a coating station (e.g., by applying an additionalcoating, e.g., gilding or other material) applying/pressing a sheet ofthe said coating onto selected areas of the substrate (e.g., comprisingan adhesive deposit in a predetermined pattern), in order for thedesired portion of the sheet of the said coating to adhere to selectedareas.

The present application describes various technical features andadvantages with reference to the figures and/or various embodiments,Those skilled in the art will understand that the technical features ofa given embodiment may in fact be combined with the features of anotherembodiment, unless the contrary is explicitly stated, or it is evident.that these features are incompatible. What's more, the technicalfeatures described in a given embodiment may be isolated from the otherfeatures of this embodiment, unless the contrary is explicitly stated.

It should be obvious to those skilled in the art that the presentinvention allows for embodiments in many other specific forms, withoutdeparting from the scope of the invention, as claimed. Therefore, thepresent embodiments should be considered to be by way of illustration,but may be modified in the field defined by the scope of the appendedclaims, and the invention should not be limited to the details givenabove.

The invention claimed is:
 1. A device for transporting substrates in aprinting machine comprising one or more treatment stations, including atleast one printing station, along a transport path from at least oneinput area supplying the printable and/or printed substrates up to atleast one output area receiving the treated substrates, comprising asubstrate conveyor for guiding and moving the substrates through thetreatment stations, the conveyor comprising at least one carriage, whichholds the substrates in a stationary position and which transports thesubstrates along the transport path; and wherein:
 1. Thesubstrate-transport device comprises a drive system for moving thecarriage along the transport path;
 2. The substrate-transport devicebeing equipped with at least one displacement detection system fordetecting displacement to measure a displacement of the carriagerelative to the transport path and at least one other displacementdetection system for measuring a displacement of the carriage relativeto one of the treatment stations; and
 3. the carriage comprises a tablefor holding the substrate in a stationary position relative to the tablealong the transport path during the treatment(s) of the substrate;wherein the displacement detection system for measuring the displacementof the carriage relative to the transport path comprises at least onedisplacement sensor “O” comprising a movable part and a fixed part, andthe displacement detection system for measuring the displacement of thecarriage relative to the treatment station(s) comprises a displacementsensor “M” comprising a movable part and a fixed part, the fixed part ofthe displacement sensor “O” is a ruler positioned along the transportpath, the movable part of the displacement sensor “O” is a readerintegrated into the carriage, the movable part of the displacementsensor “M” is a ruler fixed to the carriage, and the fixed part of thedisplacement sensor “M” is a reader integrated in the treatmentstation(s).
 2. The device for transporting substrates according to claim1, wherein the reader integrated into the carriage of the movable partof the displacement sensor “O” is an optical reader.
 3. The device fortransporting substrates according to claim 1, wherein the ruler of thedisplacement sensor “O” is linear.
 4. The device for transportingsubstrates according to claim 1, wherein the ruler of the displacementsensor “O” is optical.
 5. The device for transporting substratesaccording to claim 1, wherein the ruler of the displacement sensor “O”is positioned along a transport loop under one or more of the treatmentstations.
 6. The device for transporting substrates according to claim1, wherein the movable part of the displacement sensor “M” is a rulerfixed to the carriage along a longitudinal axis parallel to a directionof movement of the carriage.
 7. The device for transporting substratesaccording to claim 1, wherein the reader integrated into the treatmentstation(s) of the fixed part of the displacement sensor “M” is amagnetic reader.
 8. The device for transporting substrates according toclaim 1, wherein the ruler of the displacement sensor “M” is linear. 9.The device for transporting substrates according to claim 1, wherein theruler of the displacement sensor “M” is magnetic.
 10. The device fortransporting substrates according to claim 1, wherein the substrateholding table is a suction table comprising an active suction assemblyin combination with a passive suction assembly which includes astructural honeycomb layer.
 11. The device for transporting substratesaccording to claim 1, wherein the transport path is a transport loop,the conveyor comprises a fixed rail which forms the transport loop, andthe at least one carriage that maintains the substrates in a stationaryposition moves on the rail transporting the substrates, the substratetransport device being adapted to move each carriage on the rail alongthe transport loop; wherein:
 1. The substrate transport device comprisesa base on which at least a part of the rail is fixed and a surface ofwhich is flat; and
 2. the substrate transport device comprises the drivesystem which allows movement of the at least one carriage on the fixedrail.
 12. The device for transporting substrates according to claim 11,wherein the drive system is a linear motorization based on anelectromagnetic interaction between a primary assembly of coils and asecondary assembly comprising a path of permanent magnets, and theprimary assembly of the linear motorization is part of the at least onecarriage and the secondary assembly comprising the path of permanentmagnets is fixed along the transport path.
 13. The device fortransporting substrates according to claim 12, wherein the secondaryassembly is positioned in at least one manner selected from the groupconsisting of: on the fixed rail, forming an integral part of the fixedrail, being fixed to the base, forming an integral part of the base,being fixed to a rigid structure for retaining the rail, and forming anintegral part of the rigid structure.
 14. The device for transportingsubstrates according to claim 11, wherein the base consists of at leastone material selected from the group consisting of: marble, granite, andcast iron.
 15. The device for transporting substrates according to claim11, wherein the system for guiding the carriage on the fixed railcomprises at least one pair of guide elements arranged on either side ofthe rail, each pair of guide elements comprising a mechanism ensuringguidance of the carriage both in straight lines and in bends.
 16. Thedevice for transporting substrates according to claim 15, wherein themechanism ensuring guidance of the carriage comprises a retaining barwhich connects the at least one pair of guide elements, the retainingbar comprising a pivoting axis connected to the carriage making itpossible to ensure optimal guidance of the carriage along the rail andalong bends formed by the transport loop.
 17. The device fortransporting substrates according to claim 15, wherein the guide systemis a V-shaped guide system.
 18. The device for transporting substratesaccording to claim 11, further comprising at least one slide consistingof a rail and a guide element fixed to the carriage, and the slide railis positioned in at least one manner selected from the group consistingof: an integral part of the fixed rail, fixed on the fixed rail, fixedon the base of the fixed rail, an integral part of the base of the fixedrail, fixed on the supporting structure of the fixed rail, and anintegral part of the supporting structure of the fixed rail; and whereina total length of the slide rail is selected to cover an entire spacebelow the transport loop print stations.
 19. The device for transportingsubstrates according to claim 18, wherein a width of an initial endand/or a width of a final end of the slide rail is less than an averagewidth of the slide rail, and wherein the initial end is at an input areain a direction of movement of the carriage and the final end is at anoutput area in the direction of movement of the carriage.
 20. The devicefor transporting substrates according to claim 1, further comprising adevice for supplying energy to the at least one carriage, the energysupplying device comprising a set of electrically conductive rails alongthe transport path and a sliding contact element fixed on the carriage.21. The device for transporting substrates according to claim 1, furthercomprising a device for transferring information to and from the atleast one carriage, the information transferring device comprising acable system radiating along the transport path.
 22. Use of the devicefor transporting substrates according to claim 1 in a printing machinecomprising at least two different in-series, contactless printingstations and at least one drying station along the transport path. 23.Use of the device for transporting substrates according to claim 22 in aprinting machine also comprising a coating station by applying/pressinga sheet of the coating onto selected areas of the substrate, such thatthe desired portion of the sheet of said coating adheres to the selectedareas.
 24. Use of the device for transporting substrates according toclaim 1 for printed electronics, preferably for printed electronics fora radio frequency identification tag, with or without a chip.
 25. Amethod of transporting substrates in a substrate-transport deviceaccording to claim 1, in a printing machine comprising one or moretreatment stations, including at least one printing station, along atransport path from at least one input area supplying the printablesubstrates, to at least one output area receiving the treatedsubstrates, said method comprising the following steps: optionallypositioning a printable substrate in the input area prior to guiding andmoving the substrates through the one or more treatment stations; andguiding and moving at least one of the substrates through the one ormore treatment stations using a substrate conveyor, said conveyorcomprising at least one carriage which maintains the substrates in astationary position and which moves along the transport pathtransporting the substrates; wherein:
 1. The substrate-transport devicecomprises a motorization system which allows movement of the carriagesalong the transport path;
 2. The substrate-transport device is equippedwith at least one displacement system to measure a displacement of thecarriage relative to the transport path, and at least one otherdisplacement detection system to measure a displacement of the carriagerelative to the treatment station(s); and
 3. the carriage includes atable on which the substrate is held in a stationary position relativeto the table along the transport path during treatment of the substrate;4. The displacement detection system for measuring the displacement ofthe carriage relative to the transport path comprises at least onedisplacement sensor “O” comprising a movable part and a fixed part, andthe displacement detection system for measuring the displacement of thecarriage relative to the treatment station(s) comprises a displacementsensor “M” comprising a movable part and a fixed part; the fixed part ofthe displacement sensor “O” is a ruler positioned along the transportpath, the movable part of the displacement sensor “O” is a readerintegrated into the carriage, the movable part of the displacementsensor “M” is a ruler fixed to the carriage, and the fixed part of thedisplacement sensor “M” is a reader integrated in the treatmentstation(s).